Sidney Nicknamed Sid is a Dark Blue Diesel Shunter from The Other Railway.
- Season 11: Holly Jolly Molly (not named) and Trembling Trevor (not named)
- Season 12: Sidney the Renegade and Vicarstown Takedown.
- Season 13: Duck and the Quack Attack (cameo), Bert's Arlesdale Fail (cameo) and Sam I Am.
- Season 14: Millie's Castle Hassle (cameo), Freddie at the Ready (cameo), Hiro and the Heat Wave (cameo), Hugo Takes Flight (cameo) and Dirty ‘Arry
- Season 15: Philip Finds a Friend (cameo) and The Island of Misfit Engines (cameo)
- Season 16: Luke Dukes It Out (cameo) and Throw Topham from the Train (cameo)
- Season 17: Sidney Transplant and Diesel Gets the Bronze (cameo)
- Season 18: Santa Claws (cameo)
He is likely to appear in Season 18.
- Sidney Never Received a Proper introduction in Keekre24's Series. And He Only Appeared Less Than a Minute in Sodor's Last Stand.
- Although He Appeared for Less Than a Minute in Sodor's Last Stand, He Made a Cameo in The Trailer for The Movie, Claw of the Law. It is Known He will Appear.