Leonard Freeman Creator, Producer, Executive Producer Jack Lord Det. Steve McGarrett Actor James MacArthur Det. Danny Williams Actor Kam Fong Det. Chin Ho Kelly Actor Brenda Scott Donna Wales Guest Star Ed Flanders Professor David Stone Guest Star John McLiam Ralph Hastings Guest Star Susan O'Connell Eadie Hastings Guest Star Doreen Lang Sarah Hastings Guest Star Philip Leacock Producer Leonard Katzman Producer Bill Finnegan Producer Mel Goldberg Writer Seymour Robbie Director