Television
Hedison was cast in the lead of a TV series made by Fox for NBC, Five Fingers (1959). He was reluctant to make it, especially when NBC insisted he change his first name (Al) to David (which was his middle name). The series lasted only one season.
Hedison had the lead role in an adventure film The Lost World (1960), directed by Irwin Allen.
Hedison guest starred on some Fox shows, Hong Kong and Bus Stop. He co-starred with Tom Tryon in Marines, Let's Go (1961).
Hedison worked regularly on television, guest starring in Perry Mason, Wonder Woman and The Farmer's Daughter. He co-starred in an episode of The Saint, starring Roger Moore who became a great friend. The episode's plot prophetically involves Moore's Saint mistaken for 007 and Hedison as an FBI agent — roles they would play seven years later as 007 and Felix Leiter in Live and Let Die. He was one of many stars in the film The Greatest Story Ever Told (1965).
After turning down the role of Captain Crane in the film version of Irwin Allen's Voyage to the Bottom of the Sea, Allen again offered the same role to him in the television series of the same name, co-starring with Richard Basehart, which ran from 1964 to 1968.
After Voyage to the Bottom of the Sea concluded, Hedison was offered the role of Mike Brady on The Brady Bunch, but turned it down, stating, "after four years of subs and monsters, who needs kids and dogs?" The role eventually went to Robert Reed.
Hedison moved to London. "I liked London very much," he later said. "I just wanted to go and spend a couple years there ... It's two years I'm not sorry for. The problem was, when I came back to the US, it was more difficult getting work then."
Hedison guest starred on Journey to the Unknown; Love, American Style; ITV Sunday Night Theatre; the BBC's Play of the Month; The F.B.I.; and The New Perry Mason. He could be seen in Kemek (1970), A Kiss Is Just a Kiss (1971), Crime Club (1973), The Cat Creature, and The Man in the Wood. He was most proud of doing an adaptation of Summer and Smoke with Lee Remick.