Most famous for her Emmy-winning performance as Mary Campbell on the late 1970s and early 1980s ABC comedy series Soap, Damon is also notable for her role as Cassie Parker on the mid-1980s sitcom Webster.
Before beginning her television acting career, she appeared in Broadway productions of The Boys from Syracuse, Sweet Bird of Youth, and The Last of the Red Hot Lovers.
She died of ovarian cancer at the age of fifty-six.
She and her sister grew up in Seattle and Tacoma, Washington as the daughters of Mary Cathryn Springer.
She understudied Angela Lansbury in the 1967 Broadway tour of Mame.