British general in the French and Indian Wars, commander of the British forces in the failed attack on the French at Ticonderoga.

A lieutenant colonel of the Royal Scots early in his military career, Abercrombie was promoted to colonel in 1746 and served in the Flemish campaign in the War of Austrian Succession. Promoted to major general in 1756, he was ordered to accompany Lord Loudoun to America as his second in command. Abercrombie's first independent command came in December 1757, when William Pitt, at the insistence of George II, made him commander in chief. His title notwithstanding, his actions were largely determined by the ministry in London. With Augustus Lord Howe as his second in command, Abercrombie was directed to take Fort Ticonderoga by way of preparation for an assault on Montreal. Although he had a force of 15,000 British and colonial troops, Abercrombie was defeated by General Montcalm's army of 3,600 at Ticonderoga in July 1758. In September, Pitt recalled Abercrombie and gave his command to Jeffrey Amherst.

Despite his failure, Abercrombie was promoted to lieutenant general in 1759 and general in 1772. His remaining years were spent in Parliament, as deputy governor of Stirling Castle, and on his estate at Glassaugh, Banffshire.