Five ships of the Royal Navy have been named HMS Trafalgar, after the Battle of Trafalgar:
- was a 106-gun first rate launched in 1820. She was renamed HMS Camperdown in 1825, was used for harbour service from 1854 and became a coal hulk in 1857. She was renamed HMS Pitt in 1882 and was sold in 1906.
- was a 120-gun first rate launched in 1841. She was converted to screw propulsion in 1859, and was renamed HMS Boscawen in 1873. She was sold in 1906.
- was a launched in 1887 and sold in 1911.
- was a launched in 1944 and sold in 1970.
- is a launched in 1981 and decommissioned in 2009.