Orpen is an Anglo-Norman toponymic surname deriving from "Erpen" (Normandy, France). It may refer to:
- Abe Orpen (1854–1937), Canadian horse-racing track owner and casino operator, cousin of William
- Bea Orpen (1913–1980), Irish painter
- Charles Orpen (1791–1856), Irish physician, writer and clergyman
- Goddard Henry Orpen (1852–1932), Irish historian
- John Orpen (1868–1950), Anglican clergyman
- Joseph Orpen (1828–1923), British colonial administrator
- Raymond Orpen (1837–1930), Irish clergyman
- William Orpen (1871–1931), Irish portrait painter
See also
- Edward Richards-Orpen (1884–1967), Irish politician