Lieutenant general (Lt Gen), formerly more commonly lieutenant-general, is a senior rank in the British Army and the Royal Marines.

Ordinarily, lieutenant general is the rank held by the officer in command of an entire battlefield corps.

Additionally, three lieutenant general appointments also exist within the extant British Army's Headquarters.

From 1 April 1918 to 31 July 1919, the Royal Air Force maintained the rank of lieutenant general.

Additionally, the retired Royal Navy admiral John de Mestre Hutchison held an honorary RAF commission in the rank of lieutenant general.