William Kerr, 4th Marquess of Lothian

General William Henry Kerr, 4th Marquess of Lothian, KT (1710 – 12 April 1775) was a British Army officer and politician.

[6] In the same year, he was appointed lieutenant-colonel of Lord Mark Kerr's Regiment of Dragoons, and commanded the cavalry on the left wing at the Battle of Culloden in 1746 (His younger brother, Lord Robert Kerr, was with the infantry and was the highest-ranking Government casualty of the battle).

In 1752, Ancram was appointed colonel of the 11th Regiment of Dragoons, in succession to his grand-uncle Lord Mark Kerr.

He was promoted to the rank of Lieutenant General in 1758 and held a command under the Duke of Marlborough during the Raid on St Malo.

Ancram voted against the preliminaries on 9 December, having missed a message from Cumberland directing him not to do so; ultimately, he took the Chiltern Hundreds in 1763, having accepted, according to the Duke of Newcastle, £4,000 to do so.