Mortimer Ewen (5 September 1816 – 1887) was an English cricketer. Ewen's batting and bowling styles are unknown. He was born at Lodsworth, Sussex.Ewen made his first-class debut for Sussex against Kent in 1839. He made five further first-class appearances for the county, the last of which came against the Marylebone Cricket Club in 1843. In his six first-class matches for Sussex, he scored 61 runs at an average of 6.77, with a high score of 23.