Landon attended Collingswood High School and was an excellent javelin thrower, with his toss in 1954 being the longest throw by a high schooler in the United States that year. This earned him an athletic scholarship to the University of Southern California, but he subsequently tore his shoulder ligaments, putting an end to his days as a college athlete and as a student. Landon considered show-business and served as an attendant at a service gas station opposite the studios of Warner Bros. He was eventually noticed by Bob Raison, a local agent. Following advice, Landon changed his surname, selecting a new one from a phone book.