in
Bus Stop (1961) Lockwood was a film
stuntman, and a
stand-in for
Anthony Perkins prior to his acting debut in 1959 in an uncredited bit role in
Warlock. Lockwood's two series came early in his career, and each lasted only a single season.
ABC's Hawaii-set
Follow the Sun (1961–62) cast him in support of
Brett Halsey and
Barry Coe, who played adventurous magazine writers based in
Honolulu. Lockwood was Eric Jason, who did the legwork for their articles. He appeared in a supporting role in the film
Splendor in the Grass (1961) and in ABC's TV series
Bus Stop (1961). The 26-week series, which starred
Marilyn Maxwell as the owner of a
diner in fictitious Sunrise,
Colorado, aired a half-hour after
Follow the Sun. In his film debut, he appeared with Tuesday Weld in
Wild in the Country (1961), starring
Elvis Presley. Thereafter, Lockwood starred with
Jeff Bridges in the acclaimed "My Daddy Can Beat Your Daddy" episode of
The Lloyd Bridges Show. In 1959, he had an uncredited role as a police officer in the
Perry Mason episode "The Case of the Romantic Rogue". His first lead role came in 1961's
The Magic Sword, written and directed by
Bert I. Gordon. In 1962, Lockwood again appeared on
Perry Mason in the lead role in "The Case of the Playboy Pugilist". In 1963, Lockwood co-starred with
Elvis Presley in the musical-comedy film ''
It Happened at the World's Fair''. In 1963 and 1964, Lockwood starred as a young U.S. Marine second lieutenant named William T. ("Bill") Rice in the
NBC series
The Lieutenant. This drama, about the peacetime Marines, was produced by the creators of
Star Trek (
Gene Roddenberry) and
The Man from U.N.C.L.E. (
Norman Felton). The series co-starred
Robert Vaughn as Lieutenant Rice's immediate superior, Captain Raymond Rambridge. Despite moderately good reviews for
The Lieutenant, its scheduling opposite
CBS's popular ''
Jackie Gleason's American Scene Magazine'' contributed to it being cancelled after 29 episodes. In 1964, Lockwood guest-starred as Major Gus Denver in the first season of ''
12 O'Clock High, in episode 9, "Appointment at Liege", and again in 1965 in episode 29, "V For Vendetta". He also guest-starred as Lt. Josh McGraw in season 2, episode 4, "The Idolator" of 12 O'Clock High
. Shortly afterward, Lockwood starred in another NBC television series The Kraft Mystery Theater (also known as Crisis'') in an episode titled "Connery's Hands". He was cast opposite
Sally Kellerman, with whom he would soon appear again as helmsman Gary Mitchell in the second
Star Trek pilot, "
Where No Man Has Gone Before" (1965), in which their characters develop malignant super powers. In 1966, he starred as murderous bank robbing cowboy Jim Stark in a rare two-part episode of
Gunsmoke called "The Raid", along with
John Anderson,
Michael Conrad,
Jim Davis, and
Richard Jaeckel. He may be best known on the big screen for his co-starring role in
Stanley Kubrick's
2001: A Space Odyssey (1968) as Dr. Frank Poole. Lockwood was the lead in
Model Shop (1969), the American debut by French writer-director
Jacques Demy. He starred with
Elke Sommer in the crime drama
They Came to Rob Las Vegas (1968) and with
Jacqueline Bisset in the comedy
Stand Up and Be Counted (1972). Lockwood co-starred with
Stefanie Powers (then his wife) in an episode of ABC's
Love, American Style as a newlywed who gets his mouth stuck around a doorknob. In 1983, he guest-starred in the series
Hart to Hart ("Emily by Hart") with
Robert Wagner and Powers, by then his ex-wife. Between 1959 and 2004, Lockwood gained roles in some 40 theatrical features and made-for-TV movies and 80 TV guest appearances, including the
CBS 1975 family drama
Three for the Road and
Barnaby Jones starring
Buddy Ebsen, in which he appeared many times as a villain. In 2024, Lockwood again portrayed Gary Mitchell in OTOY's short film
765874 – Unification, which used digital technology to simulate his appearance in 1966. ==Personal life==