He is best known for his contributions to The Railway Series of books featuring Thomas the Tank Engine, which was started by his father, Wilbert Awdry (1911–1997).

Christopher Awdry is in a way responsible for the creation of Thomas and his railway, which started as a story told to him by his father during a bout of measles in 1942.

Christopher Awdry has written a new book for the series, titled Thomas and Victoria, which focuses on stories relating to the railway preservation movement.

In 2001, Christopher Awdry wrote six stories featured in two books concerning railway safety, which were distributed to every primary school and library in the country (Bad Days for Thomas and His Friends / More Bad Days for Thomas and His Friends).

A series of six books has been produced featuring locomotives from the Eastbourne Miniature Steam Railway, and illustrated by Marc Vyvyan-Jones.