Dexter The Boy Genius & Friends is a Cartoon Network parody of Thomas The Tank Engine & Friends.
- Set in CN City, Dexter McPherson portrays as Thomas, Finn Mertens as Edward, Ben Tennyson as Henry, Corporal Lance as Gordon, Zak Saturday as James, Steven Universe as Percy, Uncle Grandpa as Toby, Blossom as Emily, and Robert McPherson as Sir Topham Hatt.
- Dexter McPherson as Thomas (Christine Cavanaugh, Season 1-4) (Candi Milo, Season 5-present)
- Finn Mertens as Edward (Jeremy Shada)
- Ben Tennyson as Henry (Yuri Lowenthal)
- Corporal Lance as Gordon (Kevin Thoms)
- Zak Saturday as James (Sam Lerner)
- Steven Universe as Percy (Zach Callison)
- Uncle Grandpa as Toby (Peter Browngardt)
- Blossom as Emily (Catherine Cavadini, Season 1-19) (Amanda Leighton, Season 20-present)
- Robert McPherson as Sir Topham Hatt (Jeff Bennett)
- The Narrator as himself (George Carlin, Season 1-4) (Alec Baldwin, Season 5-6) (Michael Brandon, Season 7-16) (Mark Moraghan, Season 17-present)