Six ships of the Royal Navy have borne the name HMS Acorn. A seventh was planned but never completed:
HMS Acorn (1649) was a 22-gun ship hired between 1649 and 1654.HMS Acorn (1807) was an 18-gun sloop launched in 1807 and broken up in 1819.HMS Acorn (1826) was an 18-gun sloop launched in 1826 and wrecked in 1828.HMS Acorn was to have been an 18-gun sloop, but the order was cancelled in 1831.HMS Acorn (1838) was a 12-gun brig launched in 1838. She was used as a coal hulk from 1861 and was sold in 1869.HMS Acorn (1884) was a Mariner-class composite screw sloop launched in 1884 and sold in 1899.HMS Acorn (1910) was an Acorn class destroyer launched on 1 July 1910 and sold in 1921.