John Donovan Cannon, known as J. D. Cannon, was an American actor. An alumnus of the American Academy of Dramatic Arts in New York City, he is known for his co-starring role of Chief Peter B. Clifford in the NBC television series, McCloud with Dennis Weaver from 1970 until 1977, for his role as a prisoner in the film Cool Hand Luke, and for his part as the witness who cleared Dr. Richard Kimble in "The Judgment", the series finale of ABC's The Fugitive. Cannon also played General Hampton on Call to Glory and had roles in films like Lawman and Raise the Titanic.
Cannon served in the United States Army during World War II. Cannon first appeared on television as Master Sgt. Sherman in the original CBS sitcom, The Phil Silvers Show, also known as You'll Never Get Rich.
He played a recurring character - a lawman named Harry Briscoe working for the Bannerman Detective Agency - in the 1971 to 1973 western series, Alias Smith and Jones. He guest starred in many series over the years, including Wagon Train, The Untouchables, East Side/West Side, Combat!, and Stoney Burke. He was cast in several episodes of CBS's Murder, She Wrote, starring Angela Lansbury. His last television acting appearance was on NBC's Law & Order in 1991.