Don Collier (born October 17, 1928) is an actor particularly known for his role in television westerns during the 1960s. He played U.S. Marshal Will Foreman in the 1960–1962 NBC series Outlaws, with Barton MacLane (1902–1969), Jock Gaynor (1929–1998), and Bruce Yarnell (1935–1973). He appeared as a deputy marshal to MacLane in the first season of Outlaws and was promoted to full marshal in the second season, with Yarnell as the new deputy. MacLane left the series after the first season.

Collier has made more than seventy film and television appearances. He appeared with John Wayne, Robert Mitchum, Anthony Quinn, Dean Martin, Tom Selleck, James Arness, and Elvis Presley. After Massacre River, he acquired roles in Fort Apache (1948) and Davy Crockett, Indian Scout (1950) starring Fess Parker and Buddy Ebsen.

Prior to his lead role in Outlaws, Collier appeared in the first seasons of both CBS's long-running Gunsmoke (1955) and NBC's powerhouse western Bonanza (1959). He guest-starred in 1957 in NBC's Wagon Train with Ward Bond during its first year on the air. One of his earliest television appearances was in 1952 in the syndicated Death Valley Days anthology series. In 1964, he played the role of ski lodge owner Peter Hayes in the Perry Mason episode "The Case of the Fifty Millionth Frenchman." He appeared in 1965 in Chuck Connors' NBC western series Branded.

Collier appeared in three late-career Western films with John Wayne: El Dorado (1966), The War Wagon (1967), and The Undefeated (1969). In a 2016 interview, he discussed working with Wayne:

From 1967 to 1971, he was cast as Sam Butler, the ranch foreman, in sixty-two episodes of NBC's The High Chaparral, a David Dortort series with Leif Erickson, Linda Cristal, Cameron Mitchell, Mark Slade, and Henry Darrow. In 1972, he appeared in George Peppard's NBC series Banacek and in CBS's family drama, The Waltons. In 1974, he guest-starred in the initial season of Michael Landon's NBC family western drama, Little House on the Prairie. A decade later, he starred in the first season of Landon's other NBC series, Highway to Heaven, with co-star Victor French. In 1976, he appeared in an episode of the CBS western series Sara.

Collier's Cowboy image enabled him to win the designation of the "Gum Fighter" for Hubba Bubba bubble gum. In 1989, he accepted the recurring role of william Tompkins in ABC's The Young Riders, based loosely on the Pony Express (1860–1861). He has also been a sidekick of Fred Imus, younger brother of Don Imus, on Sirius Satellite Radio's weekly program, Fred's Trailer Park Bash, from 2006 until Fred's death on August 7, 2011.