The Baron is a British television series made in 1965 and 1966, based on the book series by John Creasey (written under the pseudonym Anthony Morton) and produced by ITC Entertainment. Thirty episodes were produced, and the show was exported to the American ABC network. 

John Mannering is an antiques dealer and sometime undercover agent working in an informal capacity for the head of the fictional British Diplomatic Intelligence, Templeton-Green. He is assisted by Cordelia Winfield and David Marlowe.

In Creasey's original novels Mannering was British and, after the few first entries, married. In transforming him into a bachelor and casting a Texan in the role, the producers decided that 'The Baron' would be nicknamed after the cattle ranch once run by his grandfather. In the books he was a reformed jewel-thief (the first few novels described that "career" from Mannering's decision to steal to his going straight) whose criminal ties served him well in investigating jewel, art or antiques-oriented mysteries. For the TV series, Mannering's persona was depicted as absolutely straight with no suggestion of past criminality, a fact underlined by his co-opting by British intelligence. In the episode Red Horse, Red Rider it is revealed that Mannering was in the US Army in World War II in the Monuments, Fine Arts, and Archives program where he recovered art works from the Nazis. Following the war he owned three antique stores and was a charter member of the jet set.