Jack Dunkley was born in Holloway, London, on 26 September 1906, son of William Dunkley, a housekeeper, and his wife Gertrude, both from Northampton. He left Sir Hugh Middleton Secondary School at 16 and joined the film industry in Wardour Street, producing subtitles for advertising films, and took evening classes at the Central School of Arts and Crafts. He left the film studio in 1930, and became a full-time freelance cartoonist in 1932. His earliest work was a regular sports cartoon in the Daily Mirror called "Sport Shorts". He drew sports cartoons for thirty years.
From 5 August 1957 he drew a daily strip about a working-class family, The Larks. Early scripts were written by radio comedy writers Bill Kelly and Arthur Lay. TV writer and former cartoonist Robert St. John Cooper took over from them until 1963, when he was replaced by Brian Cooke, who made the family middle class, and later by Ian Gammidge. It lasted 28 years, finally ending on 28 February 1985.
Dunkley drew two other strips for the Mirror - the cookery strip Patsy, and the gardening strip Mr Digwell, written by Gammidge - and also drew editorial cartoons and covers, including an illustration of a hand holding a gun, captioned "Today YOUR finger is on the trigger", on General Election day on 25 October 1951. He also contributed illustrations and caricatures to the Radio Times, Daily Sketch, News Chronicle, Daily Express and others. He died in March 1994 in Hendon, Middlesex.