Space cadet or similar may mean:
Fiction
- Space Cadet, a 1948 science fiction novel by Robert A. Heinlein, the origin of the expression.
- Tom Corbett, Space Cadet, a 1950s series on radio, television, and in comic books and novels
- Space Cadet, a 1965 feature in the British comic Ranger
- "Space Cadet" (Recess episode)
- "Space Cadet" (Family Guy), an episode of Family Guy
Music
- "Space Cadet", a song by Kyuss from Welcome to Sky Valley
- Space Cadet Solo Flight, a 1981 album by KC and the Sunshine Band
- "Space Cadet" (song), 2019
- "Space Cadet", a song by hip-hop artist Kollision from album Control The Streets Vol. 1
- Space Cadets, a band with Jim Capaldi on drums
- Space Cadet, a 2019 EP by Beabadoobee
Other
- Space-cadet keyboard, a keyboard layout with many modifier keys
- Space Cadet (Kid Koala), a book and soundtrack album by Kid Koala
- Space Cadets (game show), a 1997 British television comedy panel show
- Space Cadets (TV series), a 2005 British reality show
- Space Cadets (television hoax), hoax programme on British television
- Space Cadet, a table in the Full Tilt! Pinball computer pinball simulation game