Actor
- Watch the Skies!: Science Fiction, the 1950s and Us (2005) .... Dr. Edward Morbius (archive footage)
- John Ford (1993) .... Mr. Gruffydd [in "How Green Was My Valley"] (archive footage) (uncredited)
- Has Anybody Here Seen Canada? A History of Canadian Movies 1939-1953 (1979) .... Himself (at Oscar dinner, 1942, behind Jimmy Stewart) (archive footage) (uncredited)
- Sextette (1978) .... Mr. Chambers, the chairman
- Two-Minute Warning (1976) .... The pickpocket
- Won Ton Ton, the Dog Who Saved Hollywood (1976) .... Grayson's butler
- That's Entertainment, Part II (1976) .... Clip from 'Nick Carter, Master Detective' (archive footage)
- Un Sorriso, uno schiaffo, un bacio in bocca (1976) .... (archive footage)
- The Lindbergh Kidnapping Case (1976) .... Judge Trenchard
- Murder on Flight 502 (1975) .... Charlie Parkins
- You Lie So Deep, My Love (1975) .... Uncle Joe Padway
- The Lion Roars Again (1975) .... Himself (uncredited)
- The Girl on the Late, Late Show (1974) .... John Pahlman
- Harry in Your Pocket (1974) .... Casey
- Live Again, Die Again (1974) .... Thomas Carmichael
- Yellow-Headed Summer (1974) ....
- The Neptune Factor (1973) .... Dr. Samuel Andrews
- Skyjacked (1972) .... Sen. Arne Lindner
- The Screaming Woman (1972) .... Dr. Amos Larkin
- The Mask of Sheba (1970) .... Dr. Max van Condon
- House on Greenapple Road (1970) .... Mayor Jack Parker
- Rascal (1969) .... Sterling North (voice)
- Funny Girl (1968) .... Florenz Ziegfeld
- A qualsiasi prezzo (The Vatican Affair) (1968) .... Prof. Herbert Cummings
- Cosa Nostra, Arch Enemy of the FBI (1967) .... Leo Roland
- Warning Shot (1967) .... Orville Ames
- How I Spent My Summer Vacation (1967) .... Lewis Gannet
- Cinderella (1965) .... King
- Disneyland Big Red: Part 1 (1964) .... James Haggin (archive footage)
- Anniversary (1963) .... Narrator
- Advise & Consent (1962) .... Senate Majority Leader
- Big Red (1962) .... James Haggin
- Il Giorno più corto (1962) .... Hemingway
- Due colonnelli, I (Two Colonels) (1962) .... Colonello Timothy Henderson
- Voyage to the Bottom of the Sea (1961) .... Adm. Harriman Nelson
- Meet Me in St. Louis (1959) .... Mr. Smith
- Swiss Family Robinson (1958) .... Father
- The Rack (1956) .... Col. Edward W. Hall Sr.
- These Wilder Years (1956) .... James Rayburn
- Forbidden Planet (1956) .... Dr. Edward Morbius
- The Glass Slipper (1955) .... Narrator (voice) (uncredited)
- The Last Time I Saw Paris (1955) .... James Ellswirth
- Hit the Deck (1955) .... RAdm. Daniel Xavier Smith
- Deep in My Heart (1954) .... J.J. Shubert
- Men of the Fighting Lady (1954) .... Comdr. Kent Dowling
- Executive Suite (1954) .... Frederick Y. Alderson
- Dream Wife (1953) .... Walter McBride
- Scandal at Scourie (1953) .... Patrick J. McChesney
- Million Dollar Mermaid (1953) .... Frederick Kellerman
- The Bad and the Beautiful (1953) .... Harry Pebbel
- The Hoaxters (1952) .... Narrator (voice)
- The Sellout (1952) .... Haven D. Allridge
- The Unknown Man (1951) .... Dwight Bradley 'Brad' Mason
- Quo Vadis (1951) .... Narrator (voice) (uncredited)
- Calling Bulldog Drummond (1951) .... Maj. Hugh 'Bulldog' Drummond
- Soldiers Three (1951) .... Col. Brunswick
- The Miniver Story (1950) .... Clem Miniver
- Screen Actors (1950) .... Himself (uncredited)
- That Forsyte Woman (1949) .... Young Jolyon Forsyte
- The Red Danube (1949) .... Col. Michael 'Hooky' Nicobar
- Some of the Best (1949) .... Himself (uncredited)
- Julia Misbehaves (1948) .... William Sylvester Packett
- Command Decision (1948) .... Maj. Gen. Roland Goodlaw Kane
- If Winter Comes (1947) .... Mark Sabre
- Cass Timberlane (1947) .... Himself (uncredited)
- The Secret Heart (1946) .... Chris Matthews
- American Creed (1946) ....
- Holiday in Mexico (1946) .... Jeffrey Evans
- Man Hunt (1945) .... Captain Alan Thorndike
- Week-End at the Waldorf (1945) .... Chip Collyer
- The Youngest Profession (1944) .... Himself - Guest Star
- Mrs. Parkington (1944) .... Major Augustus 'Gus' Parkington
- Madame Curie (1943) .... Pierre Curie
- Mrs. Miniver (1942) .... Clem Miniver
- How Green Was My Valley (1942) .... Mr. Gruffydd
- White Cargo (1942) .... Mr. Harry Witzel
- Blossoms in the Dust (1941) .... Samuel 'Sam' Gladney
- Design for Scandal (1941) .... Jeff Sherman
- Flight Command (1940) .... Squadron Cmdr. Billy Gary
- Meet the Stars #1: Chinese Garden Festival (1940) .... Himself
- Sky Murder (1940) .... Nick Carter
- Phantom Raiders (1940) .... Nick Carter
- Dark Command (1940) .... William 'Will' Cantrell
- It's a Date (1940) .... John Arlen
- The House Across the Bay (1940) .... Tim Nolan
- I Take This Woman (1940) .... Phil Mayberry (scenes deleted)
- The Miracle of Sound (1940) ....
- Nick Carter, Master Detective (1939) .... Nicholas 'Nick' Carter, aka Robert Chalmers
- Stronger Than Desire (1939) .... Tyler Flagg
- 6,000 Enemies (1939) .... Steve Donegan
- Society Lawyer (1939) .... Christopher 'Chris' Durant
- Listen, Darling (1938) .... Richard Thurlow
- Too Hot to Handle (1938) .... William O. 'Bill' Dennis
- The Shopworn Angel (1938) .... Sam Bailey
- As Good as Married (1938) .... Fraser James
- The Girl of the Golden West (1938) .... Sheriff Jack Rance
- Man-Proof (1938) .... Alan Wythe
- A Girl with Ideas (1937) .... Mickey McGuire
- My Dear Miss Aldrich (1937) .... Kenneth 'Ken' Morley
- Saratoga (1937) .... Hartley Madison
- Girl Overboard (1937) .... Paul Stacey
- She's Dangerous (1937) .... Dr. Scott Logan
- Fatal Lady (1936) .... David Roberts
- Big Brown Eyes (1936) .... Richard Morey
- Journal of a Crime (1934) .... Florestan
- The Kiss Before the Mirror (1933) .... Lucy's Lover
- Rockabye (1932) .... Commissioner Al Howard
- The Hot Heiress (1931) .... Clay
- Kiss Me Again (1931) .... Paul de St. Cyr
- Going Wild (1930) .... 'Ace' Benton
- Her Private Life (1930) .... Ned Thayer
- Viennese Nights (1930) .... Franz von Renner
- The Gorilla (1930) .... Arthur Marsden
- Sweet Kitty Bellairs (1930) .... Lord Varney
- Bride of the Regiment (1930) .... Colonel Vultow
- Show Girl in Hollywood (1930) .... Himself - Premiere Emcee (uncredited)
- An Intimate Dinner in Celebration of Warner Bros. Silver Jubilee (1930) .... Himself
- A Most Immoral Lady (1929) .... Tony Williams
- Clothes Make the Woman (1929) .... Victor Trent
- The Voice Within (1929) ....
- Melody of Love (1928) .... Jack Clark
- Turn Back the Hours (1928) .... Philip Drake
- The Thirteenth Juror (1927) .... Richard Marsden
- Sumuru (1927) .... Paul Sinclair
- The Outsider (1926) .... Basil Owen


