"Time Crash" is a mini-episode of the British science fiction television series Doctor Who. It was broadcast on 16 November 2007, as part of the BBC One telethon for the children's charity Children in Need. Written by Steven Moffat, it starred David Tennant and brought back Peter Davison as the Doctor.

The episode, set during the last scene of the previous episode "Last of the Time Lords", depicts a humorous encounter between the Doctor's fifth and tenth incarnations, played by Davison and Tennant respectively. "Time Crash" was praised by critics who reviewed the episode, and was a ratings success; it was the most-viewed show of the night, and briefly the most-viewed episode of Doctor Who since 2005, with 11 million viewers.