She is best known for her roles on the daytime soap operas General Hospital, Santa Barbara, and All My Children. Daytime television Mattson made her daytime debut as troubled teen Hope Bauer on Guiding Light in 1976, her only complete heroine on the soaps. She received a Soap Opera Digest Award and an Emmy Nomination for her first major role as Heather Webber on General Hospital.
During Ilene Kristen"s absence from Ryan"s Hope, she played Delia Reid (1984).
Replacing Linda Gibboney on Santa Barbara, she received additional Emmy nominations as Gina Blake Lockridge, a role she played from December 1985 through the final episode in January 1993. Mattson then moved to New York to play Janet Green on All My Children (1994–2000).
Over the next few years, she took on several short term parts on The Bold and the Beautiful (2003), Madame Cheri Love on As the World Turns (2007), and Lee Michaels on Days of Our Lives (2010-2011). Mattson returned to General Hospital on two occasions, first in 2004 for six months, where she was reunited with her former Santa Barbara co-star Jed Allan, and in the spring of 2012.
Mattson has continued to play the role for storyline arcs of varying lengths as the plotline dictated.
Her most recent stint wrapped up in early 2015. and primetime television Mattson began acting at age seven. She made her screen debut in Namu, the Killer Whale (1966). She costarred in Bonnie"s Kids (1973), Candy Stripe Nurses (1974), and Return to Macon County (1975).
She appeared in a number of made for television films and guest starred in a number of primetime shows, include Marcus Welby, Doctor of Medicine, Happy Days, Barnaby Jones, Charlie"s Angels, The Dukes of Hazzard, and Law & Order.