Elizabeth Mazzocchi alleges intentional and negligent transmission of a sexually transmitted disease, assault, battery and breach of oral contract in the lawsuit, filed Thursday in Superior Court.
The lawsuit claims Morales knew he had herpes and never told Mazzocchi, leaving her with "an incurable disease that will have associated medical expenses, pain and discomfort for the rest of her life."
There was no immediate comment from Morales, the actor's publicist, Siri Garber, said Friday.
Mazzocchi's attorney, Gloria Allred, declined comment.
According to the lawsuit, Morales and Mazzocchi began their relationship in January 2006 and he moved into her Los Angeles home two months later.
Morales, 44, played police Lt. Tony Rodriguez on ABC's "NYPD Blue."
The lawsuit was first reported by the entertainment Web site CelebTV.com.