Robyn Bernard -- famous for her work on "General Hospital" -- is dead ... TMZ has learned.

Riverside County Coroner tells TMZ they identified the actress' body using her fingerprints after deputies responded to a death investigation call yesterday in the town of San Jacinto, CA. We're told Robyn's body was found in the early morning hours of March 12.

The Riverside County Coroner says no cause of death has been determined yet. An autopsy is scheduled to be performed on Wednesday, but toxicology will take several weeks.

Robyn was born in Gladewater, Texas, and eventually carved out an acting career for herself with small parts in '80s TV shows like "Diva," "The Facts Of Life," "Simon & Simon," and "Tour of Duty."

Her big break came in 1984 on the soap opera "General Hospital" ... playing the role of Terry Brock for 145 episodes until 1990.

Her final credited acting role came in 2002, when she played a psychologist in the movie, "Voices From the High School."

Since exiting the acting scene, Robyn kept a relatively private life, out of the spotlight.

She was 64.