Fynn is a surname. Notable people with the surname include:
* Charles Fynn (1897–1976), English cricketer
* David Fynn, Irish actor, producer and screenwriter
* Henry Francis Fynn (1803–1861), English traveler and trader
* James Fynn (1893–1917), English recipient of the Victoria Cross
* James Lindsay-Fynn (born 1975), British rower
* Mark Fynn (born 1985) Zimbabwean tennis player.
* Paula Fynn (born 1988), team handball player from Uruguay
* Warrick Fynn (born 1985), cricketer