Number 17 is a 1925 thriller play by the British writer Joseph Jefferson Farjeon.
It premiered at the Winter Gardens Theatre in New Brighton before beginning a West End run of 209 performances, initially at the New Theatre before transferring to Wyndham's and then the Duke of York's Theatre. The original cast included Nicholas Hannen, Fred Groves, Leon M. Lion and Nora Swinburne.
The following year he wrote a novelisation of the play, published by Hodder and Stoughton.
- Goble, Alan. The Complete Index to Literary Sources in Film. Walter de Gruyter, 1999.
- Wearing, J. P. The London Stage 1920-1929: A Calendar of Productions, Performers, and Personnel. Rowman & Littlefield, 2014.