The 103rd Light Anti-Aircraft Regiment, Royal Artillery, was an air defence unit of the British Army during World War II. Initially raised as an infantry battalion of the East Lancashire Regiment in 1940, it transferred to the Royal Artillery in 1941. It served in Northern England and Northern Ireland but saw no active service. Shortly before D Day, it was broken up to reinforce other units that fought in the campaign in North West Europe.

The East Lancashire Regiment was, from 1881 to 1958, a line infantry regiment of the British Army. The regiment was formed in 1881 under the Childers Reforms by the amalgamation of the 30th (Cambridgeshire) Regiment of Foot and 59th Regiment of Foot with the militia and rifle volunteer units of eastern Lancashire. In 1958 the regiment was amalgamated with the South Lancashire Regiment to form the Lancashire Regiment which was, in 1970, merged with the Loyal Regiment to form the Queen's Lancashire Regiment. In 2006, the Queen's Lancashire was further amalgamated with the King's Own Royal Border Regiment and the King's Regiment to form the present Duke of Lancaster's Regiment.