Harkin is an Irish surname, from the Gaelic Ó hEarcáin. It may refer to:
- Bryan Harkin (born 1980), Northern Irish footballer
- Fergal Harkin (born 1976), Irish footballer
- James B. Harkin (1875–1955), Canadian commissioner for national parks
- Janet Quin-Harkin, author
- Marian Harkin (born 1953), Irish politician
- Michael E. Harkin (born 1958), U.S. anthropologist
- Mikko Härkin (born 1979), Finnish musician
- Mo Harkin (born 1979), footballer
- Ruairí Harkin (born 1989), footballer
- Ruth Harkin (born 1944), U.S. lawyer; wife of Tom Harkin
- Terry Harkin (born 1941), Northern Irish footballer
- Tom Harkin (born 1939), U.S. politician
- William Harkin (1831–1881), Canadian doctor and politician