William Slim, 1st Viscount Slim

William Slim was born at 72 Belmont Road, St Andrews, Bristol, the son of John Slim by his marriage to Charlotte Tucker, and was baptised there at St Bonaventure's Roman Catholic church, Bishopston. He was brought up first in Bristol, attending St Bonaventure's Primary School, then St Brendan's College, before moving to Birmingham in his teens. In Birmingham, he attended St Philip's Grammar School, Edgbaston, and King Edward's School. After leaving school, his father's failure in business as a wholesale ironmonger meant that the family could afford to send only one son, Slim's older brother, to the University of Birmingham, so between 1910 and 1914 Slim taught in a primary school and worked as a clerk in Stewarts & Lloyds, a metal-tube maker.

Despite having no other connection to the university, in 1912 Slim joined the Birmingham University Officers' Training Corps, and he was thus able to be commissioned as a temporary second lieutenant into the Royal Warwickshire Regiment on 22 August 1914, on the outbreak of the First World War; in later life, as a result of his modest social origins and his unpretentious manner, he was sometimes wrongly supposed to have risen from the ranks. He was badly wounded at Gallipoli. On return to England, he was granted a regular commission as a second lieutenant in the West India Regiment. In October 1916, he rejoined the Royal Warwickshire Regiment in Mesopotamia. On 4 March 1917, he was promoted to lieutenant (with seniority back-dated to October 1915). He was wounded a second time in 1917. Having been previously given the temporary rank of captain, he was awarded the Military Cross on 7 February 1918 for actions in Mesopotamia.

Evacuated to India, he was given the temporary rank of major in the 6th Gurkha Rifles on 2 November 1918. He was formally promoted to captain and transferred to the Indian Army on 22 May 1919.

Slim became battalion adjutant with the 6th Gurkha Rifles in 1921. In 1926, he married Aileen Robertson, by whom he had one son and one daughter. Later that year Slim was sent to the Staff College, Quetta. On 5 June 1929, he was appointed a General Staff Officer, Second Grade On 1 January 1930, he was given the brevet rank of major, with formal promotion to this rank made on 19 May 1933. His performance at Staff College resulted in his appointment first to Army Headquarters India in Delhi and then to Staff College, Camberley in England (as a General Staff Officer, Second Grade), where he taught from 1934 to 1937. During this period, he also wrote novels, short stories, and other publications under the pen name of Anthony Mills, in order to further his literary interests, as well as to supplement his then modest army salary. Attending the Imperial Defence College in 1937, the following year he was promoted to lieutenant colonel and given command of the 2nd Battalion, 7th Gurkha Rifles. In 1939 he was briefly given the temporary rank of brigadier as commander of his battalion. On 8 June 1939, he was promoted to colonel (again with temporary rank of brigadier) and appointed head of the Senior Officers' School, Belgaum in India.

East African Campaign

On the outbreak of the Second World War, Slim was given command of the 10th Indian Infantry Brigade of the 5th Indian Infantry Division and was sent to Sudan. He took part in the East African Campaign to liberate Ethiopia from the Italians. Slim was wounded again during the fighting in Eritrea. On 21 January 1941, Slim was hit when his position was strafed during the advance on Agordat.

Middle East

Recovering from his wounds but still unfit for active service, Slim was temporarily employed on the General Staff at GHQ in Delhi. He was involved in the planning for potential operations in Iraq where trouble was expected. By early May 1941 Slim had been appointed Brigadier General Staff (chief staff officer) to Edward Quinan the commander designate for operations in Iraq, arriving in Basra on 7 May. Not long afterwards, Major-General Fraser, commanding Indian 10th Infantry Division, fell ill and was relieved of his command, and Slim was promoted to take his place on the 15 May 1941 in the acting rank of major-general. He led the Indian 10th Infantry Division as part of Iraqforce during the Anglo-Iraqi War, the Syria-Lebanon Campaign (where the division advanced up the river Euphrates to capture Deir ez-Zor), and the invasion of Persia. He was twice mentioned in despatches during 1941.

Burma campaign

Portrait of General Slim as commander of the Fourteenth Army, commissioned by the Ministry of Information.

In March 1942, Slim was given command of Burma Corps, also known as BurCorps, consisting of the 17th Indian Infantry Division and 1st Burma Division. Slim was made acting lieutenant general on 8 May 1942. The corps was under attack in Burma by the Japanese and, heavily outclassed by the more mobile and flexible Japanese, was soon forced to withdraw to India. On 28 October 1942, Slim was appointed a Commander of the Order of the British Empire (CBE).

Slim then took over XV Corps under the command of the Eastern Army. His command covered the coastal approaches from Burma to India, east of Chittagong. He had a series of disputes with Noel Irwin, commander of Eastern Army and, as a result, Irwin (although an army commander) took personal control of the initial advance by XV Corps into the Arakan Peninsula. The operations ended in disaster, during which Slim was restored to command of XV Corps, albeit too late to salvage the situation. General Irwin and Slim blamed each other for the result, but in the end Irwin was removed from his command, and Slim was promoted to command the new Fourteenth Army—formed from IV Corps (United Kingdom) (Imphal), XV Corps (Arakan) and XXXIII Corps (reserve) – later joined by XXXIV Corps. On 14 January 1943, Slim was awarded the Distinguished Service Order (DSO) for his actions in the Middle East during 1941. The American historians Alan Millet and Williamson Murray described Slim as: "A hardened field soldier who had learned his trade on the Western Front and in the Indian Army, Slim combined troop-leading and training skills with personal and moral courage as well as charm, a sound grasp of soldiering, and a solid appreciation of Asian warfare and the excellence of the Japanese Army. He had experienced the catastrophe of the 1942 retreat from Burma and the abortive attack on the Arakan. His honesty and character made him the obvious choice to reshape the Fourteenth Army, a force built on the Indian Army but including the ever-dependable Gurkha Rifles of Nepal, unproven infantry battalions from East and West Africa, and infantry battalions and supporting arms from the British Army".

Slim quickly got on with the task of training his new army to take the fight to the enemy. His basic premise was that off-road mobility was paramount: much heavy equipment was exchanged for mule- or air-transported equipment, and motor transport was kept to a minimum and restricted to vehicles that could cope with some of the worst combat terrain on Earth. The new doctrine dictated that if the Japanese had cut the lines of communication, then they too were surrounded. All units were to form defensive 'boxes', to be resupplied by air and assisted by integrated close air support and armour. The boxes were designed as an effective response to the tactics of infiltration practised by the Japanese in the war. Slim also supported increased offensive patrolling and night training, to encourage his soldiers to lose both their fear of the jungle and their belief that Japanese soldiers were better jungle fighters. He also instructed them to hold their positions once outflanked. The Chin hills formed a natural defensive barrier into Burma, which Slim would have preferred to outflank by an amphibious operation by landing further down the coast of Burma, but demands of the war in Europe meant the necessary landing craft were not available, forcing Slim to devise plans for advancing into Burma the hard way through the Chin hills. At the same time, the Japanese 15th Army, which formed the main striking force of the Burma Area Army, had grown from four divisions at the beginning of 1943 to eight divisions by the end of 1943 as the Japanese made preparations for invading India, which increased the difficulties of an overland advance into Burma. By 1943, the Burma Death Railway which cost the lives of thousands of slaves who built it was finished, which allowed the Japanese to reinforce the Burma Area Army, and made invading India barely possible. As Slim went about training his men for the rigours of jungle warfare, he clashed with Brigadier Orde Wingate, who took away some of Slim's best Gurkha, British and African units for his Chindit raiding group. Slim argued against the loss of his better units to Wingate, and maintained that through Wingate had a successful career in Palestine and Ethiopia, but that Wingate would discover that the Japanese were a considerably tougher foe than the Palestinians and the Italians that Wingate had hitherto been fighting. However, Slim did approve of Wingate's plans for aid to the hill tribes of Burma. The various hill peoples of Burma such as the Kachins, Karens, Chin, Nagas and the Shan collectively amounted to about 7 million of Burma's 17 million people, and unlike the Barmars who had welcomed the Japanese as liberators, had stayed loyal to the British when the Japanese invaded. The hill peoples of Burma had suffered under Japanese rule, and were more than willing to wage guerrilla warfare against them. Slim approved of the plans of the SOE and OSS to provide arms and training to the hill tribes as a way to tie down Japanese forces that would otherwise be deployed against him.

At the start of 1944, Slim held the official rank of colonel with a war-time rank of major-general and the temporary rank of lieutenant-general. In January 1944, when the Second Arakan Offensive was met by a Japanese counter-offensive, the Indian 7th Infantry Division was quickly surrounded along with parts of the Indian 5th Infantry Division and the 81st (West Africa) Division. The 7th Indian Division's defence was based largely on the "Admin Box" formed initially from drivers, cooks and suppliers. They were supplied by air, thus negating the importance of their lost supply lines. The Japanese forces were able to halt the offensive into Arakan but were unable to decisively defeat the allied forces or advance beyond the surrounded formations. In early 1944, the Japanese Prime Minister General Hideki Tojo approved of plans for victory in Asia, calling for two operations, Operation U-Go as the invasion of India was code-named and Operation Ichi-Go which was intended to defeat China once and for all. The two operations in India and China were closely linked given that American supplies for China were flown over "the Hump" of the Himalayas and the Japanese wanted to take the Assam province of India in part to close the American air bases in India that sustained China at the same time that they were launching Operation Ichi-Go, the biggest Japanese offensive of all time that involved 2 million men. The Japanese knew that they lacked the logistics to invade India, and the plans for U-Go were based on the assumption that the 14th Army would just collapse, allowing the 15th Army to capture enough food to prevent its men from starving to death. Following the 15th Army into India was the Indian National Army commanded by the fiery anti-British revolutionary Subhas Chandra Bose who had impressed Tojo with his love of violence and carnage.. The Japanese believed that the mere presence of Bose in India would inspire the men of the Indian Army to mutiny and murder their British officers, and set off an anti-British revolution that would allow the 15th Army to take all of India.

In early 1944, Slim was appointed a Companion of the Order of the Bath (CB). On 12 March 1944 the Japanese launched an invasion of India aimed at Imphal, hundreds of miles to the north. General Renya Mutaguchi of the Burma Area Army announced the invasion of India was "The March into Delhi" as he expected the invasion to end with him marching into triumph into New Delhi. Slim knew from signals intelligence that Japanese were going to invade in March 1944, but as Murray and Millet wrote "...he had little choice, but to meet it with the forces on hand-the IV Corps of three Anglo-Indian divisions-or surrender his own plans to take the general offensive into Burma in 1944." Slim chose to fight a defensive campaign to break the Japanese before launching his offensive into Burma, believing that superior British tanks, logistics and air power would allow him to inflict a decisive defeat on Mutaguchi. However, the Japanese advanced more swiftly than Slim had expected up the mud roads of Burma into India, leading to a period of crisis as the fate of India hung in balance. Slim airlifted two entire veteran divisions (5th & 7th Indian) from battle in the Arakan, straight into battle in the north. Desperate defensive actions were fought at places such as Imphal, Sangshak and Kohima, while the RAF and USAAF kept the forces supplied from the air. Slim ordered his men to hold their ground, forbade any retreat, and informed his men that were surrounded by the Japanese that supplies would be flown in from the air to allow them to hold out. Slim decided to send the IV Corps to relieve Imphal while gambling that the 5th Indian Division could hold out at Kohima, through Slim knew that if Kohima fell, then the Japanese could be able to sever the Assam railroad at Dimapur, which could cut off the 14th Army from its main supply line. The battle of Kohima was a fiercely fought battle as Murray and Millet wrote: "Nowhere in World War II-even on the Eastern Front-did the combatants fight with more mindless savagery", but Kohima held. As late as 1 June 1944, Field Marshal Alan Brooke, the Chief of the Imperial General Staff, wrote in his diary that he saw "disaster staring us in the face" in Assam, but Slim was more self-confident, believing he could smash the Japanese attempt to take India.

While the Japanese were able to advance and encircle the formations of 14th Army, they were unable to defeat those same forces or break out of the jungles along the Indian frontier. The Japanese advance stalled. The Japanese, who had a contempt for British and Indian troops based on their performance in 1941–42, refused to give up even after the monsoon started and large parts of their army were wrecked by conducting operations in impossible conditions. The initial Japanese plan was to capture Allied stocks of food, medicine and fuel to sustain their advance, but they failed to capture any stockpiles. As a result, their units took unsupportable casualties and were finally forced to retreat in total disorder in July 1944, leaving behind many dead from hunger and disease as well as their injured. Of the 150,000 Japanese soldiers who invaded India in March 1944, almost all of them were dead by July 1944 as Slim had inflicted the largest defeats that the Japanese had suffered up to this point in the war. The Indian Army remained loyal, and under its British officers fought much better than the Indian National Army. After Imphal and Kohima, the American historian Gerhard Weinberg noted for the Japanese their "...only hope in the area was propaganda by Bose, not much of a substitute for their lost 15th Army".

Unlike the Japanese who killed their own wounded, Slim went out of his way to ensure good medical care for his wounded and to evacuate via the air his wounded to hospitals in India. Slim knew his men would fight better if they knew that would receive the best possible medical care under the conditions if they were wounded. On 8 August 1944, Slim was promoted to lieutenant general, and, on 28 September 1944, he was appointed a Knight Commander of the Order of the Bath (KCB). In December 1944, during a ceremony at Imphal in front of the Scottish, Gurkha and Punjabi regiments, Slim and three of his corps commanders (Christison, Scoones and Stopford) were knighted by the viceroy Lord Wavell and invested with honours. Slim was presented with his insignia as KCB, and the others with their KBEs. Slim was also mentioned in despatches. By the end of 1944, the majority of the men serving in the British 14th Army were in fact not British as of the 12 divisions that made up the 14th Army, 2 were British, 7 were Indian and 3 came from Britain's African colonies. In addition, there were 6 Chinese divisions, 2 regiments from the U.S Army and various tribal militias made up of Shan, Chin, Naga, Kachin and Karen peoples raised by the OSS and the SOE fighting on the Allied side in Burma, requiring Slim to play the role of the diplomat as much as a general to hold these disparate forces made up of so many different peoples together.

In 1945, Slim launched an offensive into Burma, with lines of supply stretching almost to breaking point across hundreds of miles of trackless jungle. In the aftermath of Kohima and Imphal, Slim inspected the battlefields, seeing the bodies of wounded Japanese soldiers who had been killed by their comrades as under the code of Bushido, it was considered shameful to surrender and it was the highest honour for a Japanese man to die for the Emperor, which graphically showed to Slim how far the Japanese were willing to take Bushido. Slim realized that Japanese logistics had broken down, but that Japanese soldiers, motivated by Bushido were still prepared to fight to the death as the Japanese preferred to die for the Emperor rather than surrender, which led him to the conclusion that it was better to outflank and bypass the Japanese positions, leaving the main pockets of the Japanese to stave to death rather than engaging them in combat as much possible. The Burma Area Army had about 100,000 men while the 14th Army had only about 21,000 men, but Slim decided with superior mobility backed by proper supply lines that he could defeat the Burma Area Army, whose logistics were poor. The superior Japanese numbers together with the fact that the Indian Army was an all-volunteer force with only so many Indians willing to volunteer and that sending fresh British troops to Burma was not a priority in London made it imperative for Slim to save the lives of his men as much as possible. Slim was painfully aware that it would to be difficult to replace whatever losses his men took, and had no intention of having his army being ground down by fighting the Japanese in every single place that they were. The differences between Slim, who was determined to save the lives of his men as much as possible vs. the fanatical desire of Japanese officers motivated by Bushido to have every man under their command die for the Emperor led Slim to estimate that for every man killed under his command, the Japanese lost a hundred men. The American historian John W. Dower wrote that Slim's claim of 1:100 kill ratio in Burma is creditable. Slim had a close rapport with the officers and soldiers under his command, and always trusted his officers to make the correct decisions without referring to him as Slim later wrote: "I was, like other generals before me, to be saved...by the resourcefulness and the stubborn valour of my troops". Murray and Millet wrote that Slim's willingness to delegate authority down to his officers on the spot played a key role in sustaining his advance into Burma as officers did not have to wait for a decision from him.

Slim employed Billy Williams and his corps of elephants, led by Bandoola to build bridges and rescue refugees. He faced the same problems that the Japanese had faced in their failed 1944 offensive in the opposite direction. He made the supply of his armies the central issue in the plan of the campaign. The Chindwin River was spanned with the longest Bailey bridge in the world at the time. To distract the Japanese from his campaign in central and southern Burma, Slim ordered the Chinese in northern Burma to begin an offensive, which for a time led the Japanese to the erroneous conclusion that the main goal of the Allies was to open the Burma Road to China. Slim began his advance by sending two corps towards Mandalay and another corps along the coast towards Rangoon, but changed his plans when he learned from intelligence that the Japanese were planning on defending Mandalay from the eastern banks of the Irrawaddy. Slim had one corps cross the Irrawaddy south of Mandalay at Meiktila while another corps staged a feint attack on Mandalay from the north to distract the Japanese from the main blow coming up from the south. The swift flowing Irrawaddy is a wider river than the Rhine, making it into a natural defensive barrier that the Japanese believed could halt the British advance. In March 1945, after crossing the Irrawaddy the town of Meiktila was taken, followed by Burma's second city, Mandalay. The Irrawaddy river was a natural defensive barrier, but much of the countryside around the Irrawaddy consisted of plains that favored the offensive, and in his operations in the Irrawaddy river valley, Slim used combined arms offensives with artillery and tanks working closely with the infantry to bring down overwhelming firepower when the Japanese tried to block the 14th Army's advance.

The Japanese garrison in Mandalay chose not to surrender, using the forts build by the British and the maze of pagodas in downtown Mandalay to fight to the death in an urban battle that destroyed much of the city, which finally fell to the 14th Army on 20 March 1945. Slim's plan was a masterpiece of operational art, and the capture of Meiktila left most of Japan's troops stranded in Burma without supplies. The Allies had reached the open plains of central Burma, sallying out and breaking Japanese attacking forces in isolation, maintaining the initiative at all times, backed up by air-land cooperation, including resupply by air and close air support, performed by both RAF and USAAF units. Slim followed up this victory by ordering his coastal corps to seize the mouth of the Irrawaddy where it flowed into the Bay of Bengal.

In combination with these attacks, Force 136 helped initiate a countrywide uprising of the Burmese people against the Japanese. In addition to fighting the allied advance south, the Japanese were faced with heavy attacks from behind their own lines. As he advanced into Burma, Slim discovered gruesome evidence of the nature of Japanese rule in Burma, finding in village after village, Burmese peasants who had been tied to trees and bayoneted to death as the Japanese preferred bayonet practice with people rather than sandbags as normally is the case. Toward the end of the campaign, the army raced south to capture Rangoon before the start of the monsoon. It was considered necessary to capture the port because of the length of the supply lines overland from India and the impossibility of supply by air or land during the monsoon. Rangoon was eventually taken by a combined attack from the land (Slim's army), the air (parachute operations south of the city) and a seaborne invasion. Also assisting in the capture of Rangoon was the Anti-Fascist People's Freedom League led by Thakin Soe with Aung San (the future Prime Minister of Burma and father of Aung San Suu Kyi) as one of its military commanders.

As the Burma campaign came to an end, Slim was informed in May by Oliver Leese, the commander of Allied Land Forces South-East Asia (ALFSEA) that he would not be commanding Fourteenth Army in the forthcoming invasion planned for Malaya but would take command of the new Twelfth Army being formed to mop up in Burma. Slim refused the appointment, saying he would prefer to retire. As the news spread, Fourteenth Army fell into turmoil and Alan Brooke, the Chief of the Imperial General Staff, furious at not having been consulted by Leese, and Claude Auchinleck, the C-in-C India who was at the time in London, brought pressure to bear. The Supreme Allied Commander of the Southeast Asia Theatre, Louis Mountbatten was obliged to order Leese to undo the damage. On 1 July 1945, Slim was promoted to general and was informed that he was to succeed Leese as C-in-C ALFSEA. However, by the time he took up the post, having taken some leave, the war was at an end.

Relations with troops

Slim had an excellent relationship with his troops – the "Forgotten Army", as they called themselves. In his book, Defeat into Victory, he tells of the malaria rates among his units being 70%, largely due to noncompliance by his soldiers with the foul-tasting mepacrine they refused to take. Slim did not blame his medics for this problem, but placed the responsibility on his officers. "Good doctors are no use without good discipline. More than half the battle against disease is fought not by the doctors, but by the regimental officers". After Slim dismissed a few officers for high unit malaria rates, the others realised he was serious and malaria treatment was enforced, dropping the rate to less than five percent. The combat effectiveness of his army was thus greatly enhanced. This physical and mental turnaround in the army under him was a contributing factor to the eventual defeat of the Japanese in Burma.

George MacDonald Fraser, later author of The Flashman Papers series of novels, then a nineteen-year-old lance corporal, recalled:

But the biggest boost to morale was the burly man who came to talk to the assembled battalion … it was unforgettable. Slim was like that: the only man I've ever seen who had a force that came out of him... British soldiers don't love their commanders much less worship them; Fourteenth Army trusted Slim and thought of him as one of themselves, and perhaps his real secret was that the feeling was mutual.

Initial retirement from the army

At the end of 1945 Slim returned to the UK. On 1 January 1946, he was made a Knight Grand Cross of the Order of the British Empire (GBE). and took the post of Commandant of the Imperial Defence College for its first course since 1939. On 7 February 1947 he was made an Aide-de-camp (ADC) to the King. At the end of his two-year appointment at the Imperial Defence College Slim retired as ADC and from the army on 11 May 1948. He had been approached by both India and Pakistan to become C-in-C of their respective armies post independence but refused and instead became Deputy Chairman of the Railway Executive.

Return to the army

However, in November 1948 the British Prime Minister Clement Attlee rejected the proposal by Viscount Montgomery that he should be succeeded as Chief of the Imperial General Staff (CIGS) by John Crocker and instead brought back Slim from retirement in the rank of field marshal in January 1949 with formal appointment to the Army Council from 1 January 1949. Slim thus became the first Indian Army officer to be become CIGS.

On 2 January 1950, he was promoted to Knight Grand Cross in the Order of the Bath (GCB) and later that year was made a Chief Commander of the Legion of Merit by the United States having previously, in 1948, been awarded the lower ranking Commander of the Legion of Merit. On 1 November 1952, he relinquished the position of Chief of the Imperial General Staff.

Governor-General of Australia

On 10 December 1952 Slim was made a Knight Grand Cross of the Order of St Michael and St George (GCMG) on his appointment as Governor-General of Australia which post he took up on 8 May 1953. On 2 January 1953, he was appointed a Knight of the Order of St. John (KStJ). Slim was a popular choice for Governor-General since he was an authentic war hero who had fought alongside Australians at Gallipoli and in the Middle East. In 1954 he was able to welcome Queen Elizabeth II on the first visit by a reigning monarch to Australia. For his services to the Queen during the tour, he was appointed a Knight Grand Cross of the Royal Victorian Order (GCVO) on 27 April 1954. Liberal leader Robert Menzies held office throughout Slim's time in Australia. His Official Secretary throughout his term was Murray Tyrrell.

Retirement

In 1959, Slim retired and returned to Britain, where he published his memoirs, Unofficial History. He had already published his personal narrative of the Burma Campaign, Defeat into Victory, in 1956. On 24 April 1959, he was appointed a Knight Companion of the Order of the Garter (KG). On 15 July 1960, he was created "Viscount Slim of Yarralumla in the Capital Territory of Australia and of Bishopston in the City and County of Bristol". After a successful further career on the boards of major UK companies, he was appointed Constable and Governor of Windsor Castle on 18 June 1964. He died in London on 14 December 1970, aged 79 and was given a full military funeral at St. George's Chapel, Windsor and was afterwards cremated.

During his tenure as Governor-General of Australia, Slim was patron of the Fairbridge Farm child migration to Australia, which has been subject to scrutiny in recent years both in the United Kingdom and Australia. Since 2007, three former child migrants allege Slim sexually assaulted them during visits to the farms. These allegations were dismissed out of hand at that time by those who had served under Slim in the army and by his son John Slim, 2nd Viscount Slim. The allegations were aired again on ABC television in the programme The Long Journey Home, broadcast on 17 November 2009. In 2014, the Daily Mail reported that an alleged victim was pursuing the matter in an Australian court and at the Royal Commission into Institutional Child Abuse. On 27 February 2017, ABC aired another programme detailing the allegations against Slim and Fairbridge Farm, of which the Queen's uncle, Prince Henry, Duke of Gloucester, was chairman. According to one estimate by a former pupil and journalist, David Hill, some 60 percent of children who went to Fairbridge were abused.

Somehow or another, I was sat on his [Slim's] knee and, ah, um, these silky white hands were right up, because I was wearing shorts, right up my trousers and yeah, it was not, not very nice.

— Robert Stephens recounting a drive in Governor-General Slim's car, 2017

• The road William Slim Drive, in the district of Belconnen, Canberra is named after him.
• The SLAM (Single Living Accommodation Modernisation) Officers' Mess at the Royal Military Academy Sandhurst is named after him and was opened in August 2004 by his son.
• On 7 September 2008, a plaque in Slim's memory, and those who served with him, was unveiled at the Cenotaph in his native Bristol. Fr Robert King of the Diocese of Clifton was joined by faith leaders from the Hindu, Muslim and Sikh communities at the ceremony, which was led by the Lord Mayor of Bristol's chaplain, the Rev. Prebendary Harold Clarke.
• The road Viscount Slim Avenue, in Whyalla, South Australia is named after him.
• The Slim Building at the Cranfield University Shrivenham Campus is named after him.
• The Slim School was a British Families Education Service co-educational secondary school located in the Cameron Highlands, Malaya, and was named after him.

Statue of General Slim on Whitehall.

Lieutenant General Sir John Kiszely has recommended Slim's memoirs (Defeat into Victory) (1956) describing Slim as "perhaps the Greatest Commander of the 20th Century" and commenting on Slim's "self-deprecating style" Military historian Max Hastings stated:

In contrast to almost every other outstanding commander of the war, Slim was a disarmingly normal human being, possessed of notable self-knowledge. He was without pretension, devoted to his wife, Aileen, their family and the Indian Army. His calm, robust style of leadership and concern for the interests of his men won the admiration of all who served under him ... His blunt honesty, lack of bombast and unwillingness to play courtier did him few favours in the corridors of power. Only his soldiers never wavered in their devotion.

The spirit of comradeship Slim created within 14th Army lived on after the war in the Burma Star Association, of which Slim was a co-founder and first President.

A statue of Slim on Whitehall, outside the Ministry of Defence, was unveiled by Queen Elizabeth II in 1990. Designed by Ivor Roberts-Jones, the statue is one of three of British Second World War military leaders (the others being Alan Brooke and Montgomery).

Slim's papers were collected by his biographer, Ronald Lewin, and given to the Churchill Archives Centre by Slim's wife, Aileen, Viscountess Slim, and son, John Slim, 2nd Viscount Slim, and other donors, 1977–2001. Lewin's biography, Slim: The Standardbearer, was awarded the 1977 WH Smith Literary Award.