1st Regiment Royal Horse Artillery is a regiment of the Royal Horse Artillery in the British Army. It currently serves in the armoured field artillery role, and is equipped with the AS90 self-propelled gun. The regiment is currently based at Larkhill Garrison, Larkhill. The regiment completed its move from Assaye Barracks, Tidworth, to Larkhill in June 2019.

The Royal Horse Artillery (RHA) was formed in 1793 as a distinct arm of the Royal Regiment of Artillery to provide horse artillery support to the cavalry units of the British Army. Although the cavalry link remained part of its defining character, as early as the Battle of Waterloo the RHA was sometimes deployed more along the lines of conventional field artillery, fighting from comparatively fixed positions.