4th Regiment of Horse or 4th Horse may refer to:
3rd Dragoon Guards, British Army, ranked as 4th Horse from 1685 to 1746 7th Dragoon Guards, British Army, ranked as 4th Irish Horse from 1746 to 1788 4th Royal Irish Dragoon Guards, British Army, so called 1788 to 1922 4th Horse (Hodson's Horse), Indian Army