Keep It Up, Jack is a 1974 British sex comedy film directed by Derek Ford and starring Mark Jones and Sue Longhurst.

Jack James is an unsuccessful music hall entertainer and drag artist who inherits a brothel from his late aunt, and impersonates her in order to seduce the female clients.

The film also exists in a version with hardcore inserts, but there is no suggestion that any of the credited cast participated in it.

Monthly Film Bulletin said "An extended series of charades, played round a none too substantial comic theme.

The plot is left to totter haphazardly from one situation to the next, while Mark Jones zips through from one costume change to the next, displaying commendable physical facility but scarcely one memorable personality amongst all the opportunities provided.