•
The Sophomore (1929) as Sophomore Fraternity Brother (uncredited) •
Big News (1929) as Copyboy (uncredited) •
The Kiss (1929) as Pierre •
All Quiet on the Western Front (1930) as Paul •
Common Clay (1930) as Hugh Fullerton •
The Doorway to Hell (1930) as Louie •
East Is West (1930) as Billy Benson •
Many a Slip (1931) as Jerry Brooks •
Iron Man (1931) as Kid Mason •
Up for Murder (1931) as Robert Marshall •
The Spirit of Notre Dame (1931) as Bucky O'Brien •
Heaven on Earth (1931) as States •
The Impatient Maiden (1932) as Dr. Myron Brown •
The Cohens and Kellys in Hollywood (1932) as Himself •
Night World (1932) as Michael Rand •
Okay, America! (1932) as Larry Wayne •
State Fair (1933) as Pat Gilbert • ''
Don't Bet on Love'' (1933) as Bill McCaffery •
My Weakness (1933) as Ronnie Gregory •
Cross Country Cruise (1934) as Norman Winthrop • ''
Let's Be Ritzy'' (1934) as Jimmy Sterling •
She Learned About Sailors (1934) as Larry Wilson • ''
Servants' Entrance'' (1934) as Erik Landstrom •
Lottery Lover (1935) as Cadet Frank Harrington •
Spring Tonic (1935) as Caleb Enix •
Silk Hat Kid (1935) as Eddie Howard •
The Leathernecks Have Landed (1936) as Woodruff 'Woody' Davis •
Panic on the Air (1936) as Jerry Franklin •
Shakedown (1936) as Bob Sanderson •
Lady Be Careful (1936) as Chester aka Dynamite •
Murder with Pictures (1936) as Kent Murdock •
The Crime Nobody Saw (1937) as Nick Milburn •
The Last Train from Madrid (1937) as Bill Dexter • ''
Hold 'em Navy'' (1937) as Tommy Graham •
Scandal Street (1938) as Joe McKnight •
King of the Newsboys (1938) as Jerry Flynn •
Holiday (1938) as Ned Seton •
Rich Man, Poor Girl (1938) as Henry Thayer •
Young Dr. Kildare (1938) as Dr. James Kildare •
Spring Madness (1938) as Sam Thatcher •
The Ice Follies of 1939 (1939) as Eddie Burgess •
Broadway Serenade (1939) as James Geoffrey Seymour •
Calling Dr. Kildare (1939) as Dr. James Kildare •
These Glamour Girls (1939) as Philip S. Griswold •
The Secret of Dr. Kildare (1939) as Dr. James 'Jimmy' Kildare •
Remember? (1939) as Sky Ames • ''
Dr. Kildare's Strange Case'' (1940) as Dr. James 'Jimmy' Kildare •
The Golden Fleecing (1940) as Henry Twinkle •
Dr. Kildare Goes Home (1940) as Dr. James Kildare • ''
Dr. Kildare's Crisis'' (1940) as Dr. James 'Jimmy' Kildare •
Maisie Was a Lady (1941) as Bob Rawlston •
The People vs. Dr. Kildare (1941) as Dr. James Kildare • ''
Dr. Kildare's Wedding Day'' (1941) as Dr. James Kildare • ''
Dr. Kildare's Victory'' (1942) as Dr. James Kildare •
Fingers at the Window (1942) as Oliver Duffy •
The Dark Mirror (1946) as Dr. Scott Elliott •
The Unfaithful (1947) as Larry Hannaford •
The Way of Peace (1947, Short) as Narrator (voice) •
Johnny Belinda (1948) as Dr. Robert Richardson •
The Capture (1950) as Vanner •
New Mexico (1951) as Capt. Hunt •
No Escape (1953) as John Howard Tracy • ''
Donovan's Brain'' (1953) as Dr. Patrick Cory •
The Ford Show with Tennessee Ernie Ford (1958, TV series) as Father John Gerald •
The DuPont Show with June Allyson (1960, TV series) as Howard Moon •
The Barbara Stanwyck Show (NBC, 1961, TV series) as Dr. Paul Harris •
Advise & Consent (1962) as the (U.S.) Vice President – Harley Hudson •
The Carpetbaggers (1964) as 'Mac' McAllister •
Gunsmoke (1967, TV series) as Cole in "The Prodigal" •
The Big Valley (1967–1968, TV series) as Jason Fleet / Sheriff Roy Kingston •
Hawaii Five-O (1968, TV series pilot) as Governor Paul Jameson •
Here Come the Brides (1969) as Matthew Muncey •
Marcus Welby M.D. (1969) as Dr. Andrew Swanson •
My Three Sons (1970) as Professor Harper •
The Doris Day Show (1970, TV series) as William Tyler •
Earth II (1971, TV movie) as U.S. President Charles Carter Durant •
The Biscuit Eater (1972) as Mr. Ames •
The Man (1972) as U.S. Vice President Noah Calvin •
The Stranger (1973, TV movie) as Prof. Dylan MacAuley •
Battle for the Planet of the Apes (1973) as Mandemus •
Hawaii Five-O (1973, TV series) as Dr. Elias Haig in "Anybody Can Build a Bomb" (S6/Ep12) •
Hawkins (1973, TV series) in "Blood Feud" (S1/Ep4) •
The Questor Tapes (1974, TV movie) as Vaslovik •
The Magician (1974, TV series) as Max Braden in "The Illusion Of The Evil Spikes" •
Heat Wave! (1974, TV movie) as Dr. Grayson •
Columbo: Mind over Mayhem (NBC, 1974, TV series) as Dr. Howard Nicholson •
Kung Fu (ABC, 1974) as Beaumont. Nominated for an Emmy, Outstanding Single Performance by a Supporting Actor in a Comedy or Drama Series - 1975. •
Little House on the Prairie (NBC, 1976) •
The Bionic Woman (1977, TV series) as Dr. Elijah Cooper •
The New Adventures of Wonder Woman (1977, TV series) as Dr. Kenneth Wilson •
The Mary Tyler Moore Show (1977, TV series) as Doug Booth •
End of the World (1977) as Beckerman •
Damien - Omen II (1978) as Bill Atherton •
Battlestar Galactica: Saga of a Star World (1978) as Twelve Colonies President Adar • ''
Salem's Lot'' (1979, TV movie) as Jason Burke •
Little House a new Beginning (1983) as Mr McCarey •
The World of Don Camillo (1984) as Doc •
Lime Street (1985–1986) as Henry Wade Culver •
The A-Team (1986) as Bernie Greene •
Highway to Heaven (1985–1989, TV series) as Ivan Zelenka / Frank Worton / Harry Haynes ==Radio==