Born October 17, 1925 to Italian immigrants in Chicago, Mr. Gregorio attended Northwestern and Yale before making her Broadway debut in The Owl and the Pussycat as a standby alongside acclaimed director Robert Moore. Known for her gentle simplicity on the stage, she appeared on Broadway in The Investigation, Daphne in Cottage D, The Cuban Thing, and Jimmy Shine throughout the 1960s, all the while appearing on television and film in a variety of supporting parts.
In 1977, she came back to Broadway in the Pulitzer-winning The Shadow Box, where she starred opposite Geraldine Fitzgerald as the daughter of a declining old woman. The role netted Ms. Gregorio a Tony nomination, a Drama Desk nomination, and a Clarence Derwent prize.
Her later Broadway appearances, in the 1983 revival of A View from the Bridge and David Henry Hwang's M. Butterfly, were few and far between compared to her screen work, where she found success on the medical drama ER, and in the films of her husband, esteemed director Ulu Grosbard.
Ms. Gregorio is predeceased by Mr. Grosbard. She is survived by her extended family.