HMS Alexander (1778) was a 74-gun third-rate launched in 1778. She was captured by the French in 1794 but was recaptured in 1795. She was hulked in 1805 and was broken up in 1819.
Civilian vessels named Alexander in naval service:
Alexander (1813 ship), of 252 tons (bm), was built in Aberdeen. The Admiralty hired her for a discovery expedition between 1818 and 1819. She sailed with another hired vessel, Isabella.