Grehan
Grehan is a surname. Notable people with the surname include:
- Ceara Grehan, Northern Irish theatrical and opera singer
- Derry Grehan (born 1957), Canadian guitarist
- Francie Grehan, Gaelic footballer
- James Grehan (disambiguation), multiple people
- Martin Grehan (born 1984), Scottish footballer
- Stephen Grehan (born 1971), Irish retired hurler