Thomas & Friends: Hero of the Rails is a 2009 British animated adventure film and the third feature-length special based on the British television series Thomas & Friends. The film was produced and distributed by HIT Entertainment with animation production by Canadian-based Nitrogen Studios. The movie centres on Thomas finding a long-lost engine from Japan named Hiro and attempts to repair him in secret; although Spencer is on the verge of discovering Thomas' secret and getting Hiro scrapped.

This special entered pre-production in September 2008, was produced alongside the thirteenth series starting with January 2009 and was delivered in May 2009. The special marks the addition of full computer animation into the television series replacing the live-action models used previously, and the addition of a full voice cast; with voice actors Ben Small and Martin Sherman becoming the voices for Thomas the Tank Engine in the UK and US respectively.

Thomas & Friends: Hero of the Rails premiered in theatres in the United States on September 8, 2009, and later released direct-to-video in the United Kingdom on October 12.