Born in Vallejo, California, Jamison joined the ranks of stage and vaudeville performers making movies in California. Jamison's husky build and willingness to participate in messy slapstick and rowdy action guaranteed him work in silent comedies. In 1915 he was a member of Charlie Chaplin's stock company at the Essanay studio. From there he moved to the Hal Roach studio, playing hot-tempered comic foils for Harold Lloyd, Snub Pollard, and Stan Laurel. In the 1920s he joined Universal Pictures' short-comedy contingent, and later worked in Mack Sennett comedies.

Jamison had a superb tenor singing voice, and loved to sing when not filming. Sound movies gave producers a chance to exploit his singing, and for the rest of his career he would occasionally be called upon to vocalize in films. A brief series of color travelogues filmed in 1930, featured Jamison and comic Jimmie Adams as "The Rolling Stones", two singing vagabonds seeing the country. Jamison would be hired just for his singing, as in Pot o' Gold where he plays a vagrant who harmonizes in jail. He also sings "You'll Never Know Just What Tears Are" in The Three Stooges 1939 film A Ducking They Did Go.

Jamison was a Type 2 diabetic in his later years. A devout Christian Scientist, he died on September 30, 1944 at age 50 after refusing treatment for kidney cancer.