[1] He performed in vaudeville, on the radio and on stage,[1] making his Broadway debut in 1925 in a bit part in a George M. Cohan production.

Jagger decided to move into film production, helping raise money to make a feature that ultimately never was released.

[12] In April 1934, Jagger signed a contract with Paramount, for which he made You Belong to Me (1934) with Lee Tracy, then College Rhythm (1934) with Jack Oakie, Behold My Wife!

(1934) with Sylvia Sidney, Wings in the Dark (1935) with Myrna Loy and Cary Grant, Home on the Range (1935) with Jackie Coogan, Randolph Scott and Evelyn Brent, Car 99 (1935) with Fred MacMurray and Ann Sheridan, People Will Talk (1935) with Charlie Ruggles, and Men Without Names (1935) with Fred MacMurray.

Jagger played Michael Drops In in summer stock and returned to Broadway to star in Missouri Legend (1938), which ran 48 performances.

[14] He was also in short runs for Everywhere I Roam (1938–39), Brown Danube (1939), Farm of Three Echoes (1939–40) with Ethel Barrymore, and Unconquered (1940) by Ayn Rand.

He was announced for the Biblical film The Great Commandment and a biopic of Lewis and Clark with Randolph Scott, but neither was made.

[18] Instead, Jagger appeared in The Men in Her Life (1941) for Columbia, Valley of the Sun (1942) at RKO, and The Omaha Trail (1942) at MGM.

He did Driftwood (1947) for Republic and started appearing on TV shows such as The Philco-Goodyear Television Playhouse, Studio One, and The Chevrolet Tele-Theatre.

Jagger received an Academy Award for Best Supporting Actor for his role in Twelve O'Clock High (1949), made at Fox and directed by Henry King.

Jagger stayed a supporting actor, though, appearing in Sierra (1950) with Audie Murphy at Universal, Dark City (1950) for Hal Wallis, Rawhide (1951) with Hathaway and Power at Fox, and Warpath (1951) at Paramount with Edmond O'Brien and directed by Byron Haskin.

He played retired Army Major General Tom Waverly honored by Bob Wallace (Bing Crosby) and Phil Davis (Danny Kaye) in the musical White Christmas (1954), and an impotent local sheriff in the modern Western Bad Day at Black Rock (1955), starring Spencer Tracy for MGM.

He was also in The Eternal Sea (1955) at Republic, It's a Dog's Life (1955) at MGM, On the Threshold of Space (1956) at Fox, and Red Sundown (1956) at Universal.

[22] Jagger was in The 20th Century Fox Hour, Three Brave Men (1956), The Great Man (1956) (second-billed to José Ferrer), Zane Grey Theatre, "Bernadine" (1957) with Pat Boone, an episode of Playhouse 90, Forty Guns (1957) for Sam Fuller, and The Proud Rebel (1958) with Alan Ladd and directed by Michael Curtiz.

In the 1960s, Jagger increasingly worked on television appearing in The Twilight Zone ("Static"), NBC Sunday Showcase, Our American Heritage, General Electric Theater, Dr. Kildare, The Christophers, The Alfred Hitchcock Hour, and The Partridge Family.

[5] Before he left the show to have a major medical operation, though, he was less than happy with the series, clashing repeatedly with the writers and directors[5] and describing "the Mr. Novak company" afterwards as "a mishmash of unbelievable amateurishness.

He had a semiregular role on the series Matt Lincoln (1970) as the father of the title character, and parts in Vanishing Point (1971), Bonanza, and Incident in San Francisco (1971).

Jagger was in The Glass House (1972), Columbo, Kung Fu (Jagger appeared as Caine's grandfather, who wants little to do with him, but starts Caine on his series-long search for his half-brother Danny), Alias Smith and Jones, Medical Center, The Stranger (1973), The Delphi Bureau, The Lie (1973), Shaft, I Heard the Owl Call My Name (1973), Love Story, The Hanged Man (1974), The Great Lester Boggs (1974), So Sad About Gloria (1975), The Lindbergh Kidnapping Case (1976), Harry O, Hunter, End of the World (1977), and Evil Town (1977).

Dean Jagger has a star on the Hollywood Walk of Fame at 1523 Vine Street for his contribution to motion pictures.