Stanley was born Patricia Kimberly Reid. After performing in college plays and in stock she moved to New York; there she trained at the Actors Studio under Kazan and Strasberg, meanwhile working as a model. She did much work on the Broadway and London stage, winning praise and awards. To date she has appeared in only five films. For her work in Seance on a Wet Afternoon (1964) she received a Best Actress Oscar nomination; shortly afterwards she suffered a breakdown, then went 13 years before her next screen appearance. After teaching drama at a college, she returned to the screen in Frances (1982), receiving a Best Supporting Actress Oscar nomination for her portrayal of actress Frances Farmer's crazed mother.