Orpen is an Anglo-Norman toponymic surname deriving from "Erpen". It may refer to:
- Abraham Orpen (1854–1937), Canadian horse-racing track owner, casino operator,
- Arthur Orpen Herbert (1831–1890), railway commissioner
- Bea Orpen (1913–1980), Irish painter
- Charles Orpen (1791–1856), Irish physician, writer and clergyman
- Edward Richards-Orpen (1884–1967), Irish politician
- Francis Orpen Morris, (1810–1893), Irish clergyman
- John Orpen (1868–1950), Anglican clergyman
- Joseph Orpen (1828–1923), British colonial administrator
- Goddard Henry Orpen (1852–1932), Irish historian
- Raymond Orpen (1837–1930), Irish clergyman
- William Orpen (1871–1931), Irish portrait painter
