• ''
It's a Pleasure'' (1945) as Davey / Boy Referee (uncredited) •
Swamp Fire (1946) as Emile's Eldest Son (uncredited) •
No Room for the Groom (1952) as Soldier (scenes deleted) •
Francis Goes to West Point (1952) as Corporal Thomas •
Untamed Frontier (1952) as Lottie's Dance Partner (uncredited) •
Bonzo Goes to College (1952) as Jack (uncredited) •
Yankee Buccaneer (1952) as Beckett •
Back at the Front (1952) as Soldier (uncredited) •
Leave It to Harry (1954) as Quiz Show Host (short subject) •
Chief Crazy Horse (1955) as Lieutenant Colin Cartwright •
Cult of the Cobra (1955) as Rico Nardi •
Francis in the Navy (1955) as Lieutenant Anders •
The Private War of Major Benson (1955) as Young Lieutenant •
To Hell and Back (1955) as Lieutenant Lee •
All That Heaven Allows (1955) as Freddie Norton (uncredited) •
The Square Jungle (1955) as Jack Lindsay •
Never Say Goodbye (1956) as Dave Heller •
The Toy Tiger (1956) as Larry Tripps •
Francis in the Haunted House (1956) as Police Lieutenant Hopkins •
Away All Boats (1956) as Talker (uncredited) •
Mr. Black Magic (1956) as Master of Ceremonies (short subject) •
Showdown at Abilene (1956) as Verne Ward •
The Girl He Left Behind (1956) as Captain Genaro •
Lafayette Escadrille (1958) as Duke Sinclair •
Hell to Eternity (1960) as Sergeant Bill Hazen •
Dondi (1961) as Dealey •
King of the Roaring 20s – The Story of Arnold Rothstein (1961) as Arnold Rothstein •
Ring of Fire (1961) as Sergeant Steve Walsh •
Twenty Plus Two (1961) as Tom Alder •
Man-Trap (1961) as Vince Biskay •
My Six Loves (1963) as Marty Bliss •
Warning Shot (1967) as Sergeant Tom Valens •
The Green Berets (1968) as George Beckworth •
The Shoes of the Fisherman (1968) as George Faber • ''
Where It's At'' (1969) as A.C. •
Marooned (1969) as Ted Dougherty •
Generation (1969) as Jim Bolton •
Macho Callahan (1970) as Diego Callahan •
Once Is Not Enough (1975) as Tom Colt •
The Swiss Conspiracy (1976) as David Christopher •
Two-Minute Warning (1976) as Steve •
Warhead (1977) as Tony Stevens •
Golden Rendezvous (1977) as Charles Conway •
Covert Action (1978) as Lester Horton •
Inchon (1981) as David Feld (scenes deleted after premiere; final film role; filmed in 1979; released posthumously)
Television films •
Belle Sommers (1962) as Danny Castle •
Night Chase (1970) as Adrian Vico •
The Longest Night (1972) as Alan Chambers •
Moon of the Wolf (1972) as Sheriff Aaron Whitaker •
Hijack (1973) as Jake Wilkenson •
Birds of Prey (1973) as Harry Walker •
Harry O – Such Dust As Dreams Are Made On (1973) as Harry Orwell •
Pioneer Woman (1973) as Robert Douglas • ''
Harry O – Smile Jenny, You're Dead'' (1974) as Harry Orwell • ''Don't Call the Police'' (1974) as Harry Orwell •
Fer-de-Lance (1974) as Russ Bogan •
Stalk the Wild Child (1976) as Dr. James Hazard •
Mayday at 40,000 Feet! (1976) as Captain Pete Douglass •
A Sensitive, Passionate Man (1977) as Michael Delaney •
Superdome (1978) as Mike Shelley •
Nowhere to Run (1978) as Harry Adams •
S.O.S. Titanic (1979) as
John Jacob Astor •
The Golden Gate Murders (1979) as Detective Sergeant Paul Silver •
High Ice (1980) as Glencoe MacDonald •
City in Fear (1980) as Vince Perrino (released posthumously) •
Father Damien: The Leper Priest (1980) (Incomplete – Replaced by Ken Howard)
Television series •
Boston Blackie (1951) (Season 1 Episode 2: "Cop Killer") as Armored Car Driver (uncredited) •
Lux Video Theatre (1955–1956) (3 episodes) • (Season 5 Episode 30: "It Grows on Trees") (1955) as Ralph • (Season 5 Episode 51: "Perilous Deception") (1955) as Joe Davies • (Season 6 Episode 27: "It Started With Eve") (1956) as Johnny Reynolds Jr. •
Matinee Theatre (1956) (Episode 193: "Belong to Me") as Paul Merrick •
Conflict (1957) (Season 1 Episode 12: "The Money") as Sid Lukes •
You Are There (1957) (Season 5 Episode 8: "The End of the Dalton Gang (October 5, 1892)" as Grat Dalton •
U.S. Marshal (1 episode ) •
Alcoa Theatre (1957–1958) (2 episodes) • (Season 1 Episode 6: "Cupid Wore a Badge") (1957) as Mike Harper • (Season 1 Episode 20: "Decoy Duck") (1958) as Jim McCandless •
The Millionaire (1957–1958) (2 episodes) • (Season 4 Episode 14: "The Regina Wainwright Story") (1957) as Peter Miller • (Season 5 Episode 5: "The David Barrett Story") (1958) as David Barrett • ''
Dick Powell's Zane Grey Theatre'' (1957–1959) (4 episodes) • (Season 1 Episode 23: "There Were Four") (1957) as Danny Ensign • (Season 2 Episode 14: "Trial by Fear") (1958) as Tod Owen • (Season 3 Episode 1: "Trail to Nowhere") (1958) as Seth Larker • (Season 3 Episode 15: "Hang the Heart High") (1959) as Dix Porter •
Richard Diamond, Private Detective (1957–1960) (77 episodes) as Richard Diamond / Chuck Garrett •
Sheriff of Cochise (1958) (Season 3 Episode 9: "The Turkey Farmers") as Arnie Hix •
Westinghouse Desilu Playhouse (1959) (Season 1 Episode 25: "Two Counts of Murder") as Ross Ingraham •
Death Valley Days (1961) (Season 9 Episode 18: "Deadline at Austin") as Dr. Bill Breckenridge •
Adventures in Paradise (1961) (Season 3 Episode 6: "Show Me a Hero") as Scotty Bell •
Naked City (1961–1963) (2 episodes) • (Season 3 Episode 5: "A Wednesday Night Story") (1961) as Blair Cameron • (Season 4 Episode 26: "On the Battle Front: Every Minute is Important") (1963) as Carl Ashland •
Thriller (1962) •
Target: The Corruptors (1962) (Season 1 Episode 19: "The Middle Man") as Robbie Wilson •
General Electric Theater (1962) (Season 10 Episode 20: "Shadow of a Hero") as Pat Howard •
Follow the Sun (1962) (Season 1 Episode 24: "A Choice of Weapons") as Johnny Sadowsky •
Checkmate (1962) (Season 2 Episode 25: "Ride a Wild Horse") as Len Kobalsky • ''
Cain's Hundred'' (1962) (Season 1 Episode 26: "Inside Track") as Dan Mullin •
Kraft Mystery Theatre (1962) •
Route 66 (1962) (Season 3 Episode 1: "One Tiger to a Hill") as Karno Starling •
The Eleventh Hour (1962) (Season 1 Episode 3: "Make Me a Place") as Hal Kincaid •
The Dick Powell Show (1963) (Season 2 Episode 23: "Thunder in a Forgotten Town") as Kenneth 'Ken' Morgan •
The Fugitive (1963–1967) (120 episodes) as Dr. Richard Kimble / varied aliases •
The Hollywood Palace (1965) • ''
O'Hara, U.S. Treasury'' (1971–1972) (23 episodes) as James O'Hara / Jim O'Hara •
Cannon (1973) (Season 3 Episode 1: "He Who Digs a Grave") as Ian Kirk •
Harry O (1973–1976) (45 episodes) as Harry Orwell •
Police Story (1977) (Season 5 Episode 1: "Trigger Point") as Sergeant Joe Wilson •
The Word (1978) (miniseries) (all 4 episodes) as Steve Randall •
Centennial (1978–1979) (Narrator for all 12 episodes) (10 episodes as Paul Garrett) •
Biography (1979) as Host ==Bibliography==