The John Forsythe Show began as a situation comedy in the fall of 1965 on NBC, but at mid-season it switched to a spy show. In the first phase of the series, John Forsythe appeared as United States Air Force veteran John Foster, who inherited the private Foster School for Girls in San Francisco, California, from his late aunt, Victoria. Forsythe's co-stars were Elsa Lanchester as the principal, Miss Culver; Ann B. Davis, as the physical education teacher, Miss Wilson; and Guy Marks as Ed Robbins, Forsythe's aide and a former sergeant. Actors who portrayed students included Pamelyn Ferdin as Pamela, Darlene Carr as Kathy, Page and Brooke Forsythe (Forsythe's actual daughters) as Marcia and Norma Jean, Peggy Lipton as Joanna, Tracy Stratford as Susan, and Sara Ballantine as Janice.
NBC advertising in February, 1965, gave a working title of The Mr. and The Misses.
When the format changed to espionage, it was explained to viewers that Major Foster had been recalled to active duty as a secret agent. All the other regulars except Forsythe and Marks were dropped from the cast. Peter Kortner was the producer of the series, which twice aired twenty-two episodes from September 13, 1965, to August 29, 1966. The series was produced by Forsythe's own company in conjunction with Universal Television Studios. Earl Bellamy was the director.
Selected episodes include "'Tis Better to Have Loved and Lost" with Kim Darby, "Duty and the Beast" with Harvey Korman and Sandra Smith, "Engagement, Italian Style" with stuntman Dick Shane, "Little Miss Egghead" with Angela Cartwright, "That Little Old Matchmaker" (also with Sandra Smith), "The Bainbridge Curse", and the series finale, "Get Me to the Execution on Time".
The John Forsythe Show aired on Mondays at 8 p.m. Eastern following the Hullabaloo music program and preceding Dr. Kildare starring Richard Chamberlain. Its competition was Garry Moore's quiz program, I've Got a Secret on CBS, and the second half of the military drama Twelve O'Clock High starring Robert Lansing, Paul Burke, and Robert K. Dornan.