David Fynn is a British-Irish actor, producer and screenwriter, best known for playing Brett in the NBC TV sitcom Undateable.

He began playing Dewey Finn in the West End cast of Andrew Lloyd Webber's musical School of Rock (based on the 2003 film with Jack Black) in October 2016 at the New London Theatre, for which he received an Olivier Award nomination for Best Actor in a Musical in 2017.