Annette began acting at a very young age doing guest appearances in shows such as My Three Sons (1960), The Virginian (1962), Gunsmoke (1955), and The Partridge Family (1970).
Although she appeared in a number of television and theatrical movies from 1973 onward (notably as Tammy Wynette in 1981's Stand By Your Man), her first major role was as Nick Nolte's loyal girlfriend in 48 Hrs. (1982). In the same year, she appeared opposite Nastassja Kinski in Cat People.
1983 saw her play the part of Lois Lane's arch-rival Lana Lang in Superman III (1983)
In 1990 she starred in a remake of A Girl of the Limberlost, and in Stephen King's "It".
She had a recurring roles on the television show Nash Bridges (1996), and The Huntress (2000). She has also performed in a number of successful theater productions. In October 2001, she returned to the Superman mythos in the role of Martha Kent, Clark Kent/Superman's mother, in the television series Smallville, a role she continues to play today. Annette has been married to actor Michael McKean since 1999.