Looking for Mr. Goodbar is a 1977 American crime drama film, based on Judith Rossner's best-selling novel of the same name, which was inspired by the 1973 murder of New York City schoolteacher Roseann Quinn. The film was written and directed by Richard Brooks, and stars Diane Keaton, Tuesday Weld, William Atherton and Richard Gere.
Set in the mid-1970s, the film traces the sexual awakening of Theresa Dunn (Keaton), a young Irish-American teacher searching for excitement outside her ordered life. While in college, Theresa lives with her repressive Polish-Irish Catholic parents, and suffers from severe body image issues following a childhood surgery for scoliosis that left a large scar on her back. Theresa later finds out that her scoliosis is congenital and that her aunt had the same condition and committed suicide. As a result, Theresa is reluctant to have children of her own. Meanwhile, her beautiful "perfect" older sister, Katherine (Weld), has left her husband and embarked on a wild lifestyle involving multiple affairs, a secret abortion, recreational drug use, and a short-lived marriage to a Jewish man. Theresa finds first love and loses her virginity with her much older, married college professor Martin (Alan Feinstein), who ends the affair just before her graduation, leaving Theresa feeling used and lonely.
Theresa takes a job teaching deaf children, and proves to be a gifted and caring teacher. With Katherine's encouragement, she moves out of her parents' home into an apartment in Katherine's building. She frequents a bar at night where she meets a charming but vain Italian-American character named Tony (Richard Gere) who she ends up sleeping with, and taking cocaine with. He leaves in a hurry and gives her a Quaalude pill to counteract the cocaine, but this causes her to oversleep and arrive very late for work the next day, angering her employer and students. Tony then disappears for a long while. Theresa misses him initially.
Through her job, Theresa also meets and dates an Irish-American welfare caseworker named James (Atherton). Her parents approve of the responsible James, seeing him as a potential husband for Theresa. However, the couple do not have sex and James wants a traditional courtship and monogamous relationship, which Theresa sees as stifling her freedom. Although James initially seems nice, over time he appears to become controlling and disrespectful of Theresa.
Meanwhile, Theresa begins to go out to more marginal places and have sex with complete strangers, often older men.
Tony eventually returns and acts as if nothing had happened. He barges in on Theresa while she is with another man and chases the man away. He becomes controlling and abusive, and Theresa also discovers that he is a street hustler. She breaks up with him, but he then stalks and harasses her at home and at the school where she works. After imagining what could happen if Tony were to turn her in to the police as revenge, Theresa gathers up all the drugs in her apartment and flushes them down the toilet.
With the new year approaching, Theresa resolves to turn over a new leaf and take control of her life. Seeking one final hookup on New Year's Eve, Theresa picks up Gary (Tom Berenger), a sexually confused ex-convict, who tells Theresa he has a pregnant wife in Florida, but has been living at the expense of other lovers who, it is strongly implied, are affluent gay men, since coming to the city. Although Gary is attracted to Theresa, when they are in bed together at Theresa's apartment, Gary finds himself unable to achieve an erection. He then sniffs a "popper". Theresa tells him it's OK to not have sex, which Gary misinterprets as questioning his sexuality. In a rage, Gary attacks her, rapes her, and then stabs her repeatedly with a knife, killing her in an orgy of blood and drug-induced surrealism.
The film opened to mixed reviews, but solid box office. Many critics praised Diane Keaton's performance. The film currently holds a "fresh" 76% rating on Rotten Tomatoes, with the consensus "Diane Keaton gives an absolutely fearless performance in a sexual thriller whose ending will leave audiences trembling".
Some critics found the film lurid and muddled; a review by Frank Rich for Time magazine criticized Brooks for making "many crude miscalculations" in adapting the novel. Roger Ebert gave the film 3 out of 4 stars, praising Keaton's performance but lamenting the "many loose ends and dead ends", some of which he blamed on significant alterations to the novel's plot. John Simon noted that while the novel is set in New York City, the film is said to be located in San Francisco (but identifiably filmed in Chicago's Rush Street neighborhood). He also noted that "the main character is made considerably prettier, thus reducing the principal sources of her insecurity," as compared to her portrayal in the novel.
Author Judith Rossner "detested" the film, although she praised Keaton's performance. Judith Rossner added "I feel like the mother who delivered her 13-year-old daughter to the door of Roman Polanski and didn't know what was going to happen." 
The film also inspired the music video for the 1993 Madonna song "Bad Girl". In the video Madonna plays a woman who like Theresa engages in self-destructive behavior by drinking heavily and sleeping around with random men before she is ultimately murdered by a one night stand.
Diane Keaton was nominated for the Golden Globe Award for Best Actress (Drama) and the New York Film Critics Circle Award for Best Actress. She was not nominated for an Academy Award for this film, but she won Best Actress the same year for Annie Hall.
Director Richard Brooks was nominated for "Best Drama Adapted from Another Medium" from the Writers Guild of America.