Upstairs at the Gatehouse is an Off West End theatre in Highgate in the London Borough of Camden.

The venue is a refurbished 1895 auditorium, upstairs from the Gatehouse pub, which has served over the years as a music hall, cinema, Masonic lodge, and a jazz and folk music club.

Upstairs at the Gatehouse was created by Ovation Theatres Limited (directors John and Katie Plews).

The company has owned the theatre since 1997.

[citation needed] TimeOut described it in 2010 as "one of London's most reliable fringe musical theatre venues".