The 4th Royal Irish Dragoon Guards was a cavalry regiment in the British Army, first raised in 1685. It saw service for three centuries, before being amalgamated into the 4th/7th Dragoon Guards in 1922. In 1921, it was retitled the 4th Royal Irish Dragoon Guards and in 1922 was amalgamated with 7th Dragoon Guards (Princess Royal's), to form the 4th/7th Dragoon Guards.