Johnson made her film debut in the 1977 drama film Opening Night directed by John Cassavetes and starring Gena Rowlands.
1979
From 1979 to 1980, she had a recurring role as Betty Lou Barker in the CBS prime time soap opera Dallas.
1983
She is best known for playing Terry Hartford in the CBS primetime soap opera Falcon Crest from 1983 to 1986.
In 1983, she was cast as Terry Hartford in another CBS prime time soap opera, Falcon Crest playing this role to 1986.
1985
Johnson appeared in a number of movies, include Beyond Reason (1985), Wes Craven's Chiller (1985), Fatal Instinct (1992), Trauma (1993), Deadly Exposure (1993), Four Christmases (2008) and Fame (2009).
She was first married to producer David Solomon, and then to actor Harry Hamlin from 1985 to 1989.
1986
In 1986, she received a Soap Opera Digest Award nomination for Outstanding Villainess on a Prime Time Serial.
1988
From 1988 to 1989, she played one of leads in the ABC medical drama series Heartbeat produced by Aaron Spelling.
1998
From 1998 to 1999, she played a leading role in the syndicated television family drama Born Free.
Johnson also guest starred in a number of shows, include Hotel, L.A. Law, In the Heat of the Night, Nash Bridges, Strong Medicine and Monk.