John Ashton Cannon CBE FRSA (born Hertfordshire, 8 October 1926, died Newcastle upon Tyne 25 October 2012) was an English historian specialising in 18th-century British politics. Cannon was educated at Hertford Grammar School where he gained a scholarship to Peterhouse, Cambridge, and gained his PhD at Bristol University (where he was appointed Lecturer in 1961 and Senior Lecturer in 1967 as well as Reader in 1970). During his time at Bristol, he also became involved in Radio Bristol when it was first aired and was Chairman from 1970 to 1974.