Johnson was born in Decorah, Iowa, to George and Helen Johnson. She attended Decorah High School, Luther College and Northwestern University before becoming an Actress in 1952. She appeared on stage, on television and films, with roles in Short Cut to Hell (1957), Midnight Cowboy (1969), From the Mixed-Up Files of Mrs. Basil E. Frankweiler (1973), Health (1980), The Day After (1983), The Slugger's Wife (1985), Murphy's Romance (1985) and Quicksilver (1986).