Belle is a British Railways Standard Class 4 tank engine.
Belle is painted royal blue with red and brass fittings. She has the number 6120 painted in gold and a crest consisting of a flame, two dolphins, and a crown painted on her sides. Her wheels are red with blue rims.
- Season 13: Duck and the Quack Attack (cameo; not named), It's Good To Be Belle, Sideplates and Skirmishes (cameo) and How Gator Stole Christmas (cameo)
- Season 14: Millie's Castle Hassle (cameo), Quarry Quest (cameo), Hiro and the Heat Wave, Merlin the Magical Engine (cameo)
- Season 15: Ice Ice Daisy (cameo)