In film he is known for his roles as Tom Frank in Robert Altman's Nashville, E. J. Bellocq in Louis Malle's Pretty Baby, and Mickey in Alan Rudolph's Choose Me.

On television he is known for his roles as Wild Bill Hickok on the HBO series Deadwood, FBI agent Frank Lundy on the Showtime series Dexter, Lou Solverson in the first season of FX's Fargo, Penny's father Wyatt on the CBS sitcom The Big Bang Theory, and U.S. President Conrad Dalton on the CBS political drama Madam Secretary.

[6] After high school, Carradine entertained the thought of becoming a forest ranger, and enrolled at Colorado State University in Fort Collins.

He won the Outer Critics Circle Award for Foxfire with Hume Cronyn and Jessica Tandy, and appeared as Lawrence in Dirty Rotten Scoundrels at the Imperial Theater.

In 2008, he appeared as Dr. Farquhar Off-Broadway in Mindgame, a thriller by Antony Horowitz, directed by Ken Russell, who made his New York directorial debut with the production.

"[12] In 1977, Aldrich said "I think that Keith Carradine, if he's careful—I don't think he is careful—and if he's prudent about the selection of his parts, can be a great big movie star.

He has acted in several offbeat films of Altman's protege Alan Rudolph, playing a disarmingly candid madman in Choose Me (1984), an incompetent petty criminal in Trouble in Mind (1985), and an American artist in 1930s Paris in The Moderns (1988).

Carradine traveled to Tuscany in 2012 to executive produce and star in John Jopson's Edgar Allan Poe inspired film Terroir.

In 2016, Carradine returned to star in his fourth Alan Rudolph film Ray Meets Helen, which was the final screen appearance of Sondra Locke.

[14] His brother, David, said in an interview that Keith could play any instrument he wanted, including bagpipes and the French horn.

This led to a brief singing career; he signed a contract with Asylum Records and released two albums – I'm Easy (1976) and Lost & Found (1978).

[16] In 1972, Carradine appeared briefly in the first season of the hit television series, Kung Fu, which starred his brother, David.

His performance in Chiefs earned him a nomination for an Emmy Award in the "Outstanding Supporting Actor in a Limited Series or a Special" category.

[17] Carradine also starred in the ABC sitcom Complete Savages, and he played Wild Bill Hickok in the HBO series Deadwood.

Carradine hosted the documentary Wild West Tech series on the History Channel in the 2003–2004 season, before handing the job over to his brother, David.

In the 2005 miniseries Into the West, produced by Steven Spielberg and DreamWorks, Carradine played Richard Henry Pratt.

During the second and fourth seasons of the Showtime series Dexter, he appeared numerous times as FBI Special Agent Frank Lundy.

Carradine is credited with guest starring twice on the suspense-drama Criminal Minds, as the psychopathic serial killer Frank Breitkopf.

Other shows he appeared in include The Big Bang Theory (as Penny's father Wyatt), Star Trek: Enterprise ("First Flight" episode) and the Starz series Crash.

[7] In 2006, Will pleaded guilty to two counts of perjury for lying to a grand jury about her involvement in the Anthony Pellicano wire tap scandal.