Thomas's friends are also anthropomorphic locomotives and rolling stock who live on the Island of Sodor, where the stories are set. These include:
- Edward: A blue tender engine who is Thomas's best friend.
- Henry: A green tender engine who is strong but timid.
- Gordon: A large blue express engine who is proud and sometimes boastful.
- James: A red tender engine who is vain and arrogant.
- Percy: A small green tank engine who is cheerful and eager.
- Toby: A brown tram engine who is wise and gentle.
- Henrietta: Toby's faithful brake van.
- Annie and Clarabel: Thomas's two faithful coaches.
The characters of Thomas and Friends are beloved by children around the world and have been featured in numerous books, television series, films, and other media.