A spin-off is a series who takes place in the same universe as "Inspector Spacetime" and usually borrows some characters from the original show. Because of its long run, it produced several spin-offs.
- FE-Line and Friends (1980)
- Peacemist: Nicer Post (2005–2010)
- The Mary Sue Predicaments (2006–2011)
- FE-Line (2008–2013)
- Break (2015–present)