Thomas & Friends: Hero of the Rails is a 2009 British animated adventure film and feature-length special of the British television series, Thomas & Friends. The film is produced by HIT Entertainment with animation from Nitrogen Studios. It introduces full CGI animation replacing live-action models, and the addition of a voice cast for the characters alongside the narration to the TV series.The film features the voice of Ben Small and Martin Sherman as Thomas the Tank Engine for the UK and US respectively. It was first released on DVD and on iTunes on 12 January 2010. To promote the film a "Day Out with Thomas 2010: The Hero of the Rails Tour" was held at locations such as the Illinois Railway Museum, where guests could participate in activities such as arts and crafts or ride on a 15-ton replica of Thomas the Tank Engine.A mobile app (Thomas & Friends: Hero of the Rails) was released in May 2011. The DVD was also released in 2019 in "The Heroic Collection" along with Misty Island Rescue, Day of the Diesels, Blue Mountain Mystery, and Tale of the Brave.This special takes place between the twelfth and thirteenth seasons of the television series.

In the film, Thomas discovers an old, dilapidated engine in the woods, and tries to repair him in secret, without the villainous Spencer finding out.