William FitzClarence, 2nd Earl of Munster

William FitzClarence, 2nd Earl of Munster, (19 May 1824 – 30 April 1901), styled Viscount FitzClarence from 1831 to 1842, was a British peer, and the grandson of King William IV, whom he was named after, and who died in 1837, aged almost 72, when the younger William was just 13.

FitzClarence's father, George FitzClarence, 1st Earl of Munster, was an illegitimate son of King William IV by his long-time mistress Dorothea Jordan. Therefore, the second Earl of Munster was the great-grandson of King George III. His mother was Mary Wyndham (d. 3 December 1842), the illegitimate daughter of George O'Brien Wyndham, 3rd Earl of Egremont.

FitzClarence was married to his first cousin Wilhelmina Kennedy-Erskine (27 June 1830 – 9 October 1906) on 17 April 1855. In later life, she became a novelist. They had nine children;

• Edward, Viscount Fitz-Clarence (29 March 1856 – 1870)
• Hon. Lionel Frederick Archibald (24 July 1857 – 24 March 1863)
• Maj. Geoffrey George Gordon, 3rd Earl of Munster (18 July 1859 – 2 February 1902); died without issue
• Hon. Arthur Falkland Manners (1860–1861)
• Aubrey, 4th Earl of Munster (7 June 1862 – 1 January 1928); died without issue
• Hon. William George (17 September 1864 – 4 October 1899)
• Hon. Harold Edward (15 November 1870 – 28 August 1926); his son was the 5th Earl of Munster
• Lady Lillian Adelaide Katherine Mary (10 December 1873 – 15 July 1948)
• Lady Dorothea Augusta (5 May 1876 – 28 January 1942)

He succeeded the Earldom of Munster on the suicide of his father, 20 March 1842. For the most part, FitzClarence led a typical Victorian upper-class life of hunting parties and balls.

He purchased a commission as ensign and lieutenant in the Scots Fusilier Guards on 1 July 1842. On 7 April 1843, he purchased a cornetcy and sub-lieutenancy in the Grenadier Guards. He purchased a lieutenancy on 1 May 1846 and a captaincy on 16 March 1849. Munster retired from the Army in April 1851.

He died, at 23 Palmeira Square, Hove, at the age of 77, when his cousin Edward VII was on the throne of the United Kingdom. He was buried at Cuckfield, Sussex.

He was succeeded as Earl by his third son, Geoffrey George Gordon.