Ghalib ibn Abd Allah al-Laythi, also known as Ghalib ibn Fadala al-Laythi (fl. 624 – c. 671), was an early companion and commander of the Islamic prophet Muhammad. During the prophet's lifetime, he led several expeditions against the polytheistic Bedouin tribes. He later participated in the conquest of Iraq in 634–636 and briefly as a commander in Khurasan in 668–671.
Ghalib ibn Abd Allah belonged to the Kalb clan of the Arab tribe of Banu Layth, itself part of the tribe of Banu Bakr ibn Abd Manat. He became an early companion of the Islamic prophet Muhammad and commanded several military campaigns under his authority. As early as 5 April 624, Muhammad dispatched Ghalib from Medina to lead a raid against the nomadic tribes of Ghatafan and Banu Sulaym. Three Muslims and a number of the tribesmen were slain, their livestock was captured and Ghalib returned to the city six days later. He later led a raid in al-Mayfa'a in the Najd (central Arabia), some distance from Medina, against the Banu Murra in January 629, during which a tribesman of the Juhaynah, allied with the Banu Murra, was killed. At another point in the year, Ghalib led an expedition of 130 men against the Banu Abd ibn Tha'laba clan, in which their camels and sheep were captured. In May, Muhammad sent him to lead thirteen to nineteen men in an attack against the Banu al-Mulawwih clan of Ghalib's Banu Layth tribe at the village of al-Kadid, 38 kilometers west of Mecca, in the Hejaz (western Arabia), in which some Laythi tribesmen were slain.
Though the historian Hisham ibn al-Kalbi (d. 819) notes that Ghalib died at the Fadak oasis during the lifetime of Muhammad, who died in 632, the historian Ibn Hajar (d. 1449) claims this to be erroneous. During the caliphate of Umar (r. 634–644, Ghalib was dispatched at the head of a contingent of Kinana tribesmen to join the commander al-Muthanna ibn Haritha at the Battle of Buwayb in Iraq in November 634. He later participated in the Battle of Qadisiyya, including as a dueler, in November 636.
During the governorship of Ziyad ibn Abihi in Basra, the Muslim Arabs garrison town in Iraq and springboard for the conquest of the Sasanian Empire, Ghalib was appointed to replace the commander al-Hakam ibn Amr al-Ghifari in Khurasan in 668/69, following the death of al-Hakam. He was tasked with continuing al-Hakam's efforts to subdue the principalities of Tukharistan, which had rebelled against Arab authority. He was ultimately unsuccessful and replaced in 671 by Rabi ibn Ziyad al-Harithi.