Kevin Hagen (April 3, 1928 – July 9, 2005)[1] was an American actor best known for his role as Dr. Hiram Baker on NBC's TV series Little House on the Prairie.

[citation needed] Hagen's first regular role on a series was in 1958 playing John Colton, the city administrator of New Orleans in the CBS Western Yancy Derringer.

Hagen guest-starred on Gunsmoke, The Big Valley, Bonanza, Laramie, Have Gun - Will Travel, Mannix, The Time Tunnel, and Perry Mason.

Other appearances included Tales of Wells Fargo, The Untouchables, Bat Masterson, Riverboat, The High Chapparal, Wagon Train (S1 E21 "The Annie MacGregor Story" 1958 and S8 E25 “The Silver Lady” 1965), Outlaws, Straightaway, GE True, Hawaiian Eye, Voyage to the Bottom of the Sea, The Twilight Zone, Daniel Boone, Blue Light, Mission: Impossible, Rawhide, 77 Sunset Strip, M*A*S*H, The Rifleman (as Billy St.John in S2 E31 "The Prodigal" 1960), Lancer, The Virginian, The Guns of Will Sonnett, The Cowboys, Lost in Space, The Silent Force, Sara, Quincy, M.E., Simon and Simon, and Knots Landing.

Hagen played a Confederate renegade who kills James Stewart's son and daughter-in-law in the 1965 film Shenandoah.