Three ships of the Royal Navy and Royal Fleet Auxiliary have been named Sir Galahad, after the knight of Arthurian legend.

• HMS Sir Galahad (T226) was a Round Table-class trawler used as a minesweeper in World War II
• RFA Sir Galahad (1966) (L3005), a landing ship (logistic), was lost in the Falklands War
• RFA Sir Galahad (1987) (L3005), a landing ship (logistic) named for (and given the same pennant number as) the previous Sir Galahad, was involved in the 2003 invasion of Iraq