Leslie Theodore Lyall (14 November 1905, Chester, England – 14 February 1996, Tunbridge Wells, England) was a British Protestant Christian missionary in China. He also authored several books about China. He served with the China Inland Mission.

Lyall was born in Chester, England, the son of an itinerant evangelist who died when Leslie was five years old. Educated at Emmanuel College, Cambridge, Lyall was a leader of the Cambridge Inter-Collegiate Christian Union in the period that the Inter-Varsity Fellowship of Evangelical Unions was coming into being.^[1]