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

Hagen was the son of professional ballroom dancers, Haakon Olaf Hagen and Marvel Lucile Wadsworth. His father abandoned the family when Kevin was five. He was raised by his mother, grandmother, and two aunts, with some help from his uncle, a physician. The family moved to Portland, Oregon, when Kevin was a teenager. He played baseball and football at Jefferson High School. He attended Oregon State University before enlisting in the U.S. Navy after World War II; he served in San Diego.

Hagen, married four times, was a single parent for two decades to his son, Christopher Hagen, a Special Education teacher and high school baseball coach in Bakersfield, California.