Wealthy American businessman Robert Talbot (Rock Hudson) owns a villa on the Ligurian coast, where he and his Roman mistress Lisa Fellini (Gina Lollobrigida) spend September of each year. When Robert moves up his annual visit to July and calls her en route from Milano, she cancels her wedding to Englishman Spencer (Ronald Howard) and rushes to meet him. Upon his arrival at the villa, Robert discovers that, in his absence, his major domo, Maurice Clavell (Walter Slezak), has turned the villa into a hotel, currently hosting a group of teenage girls, including Sandy (Sandra Dee), and their chaperone, Margaret Allison (Brenda De Banzie). Their departure is delayed when Margaret slips on the cork of a champagne bottle opened by Robert and is forced to spend a day in the hospital. Four teenage boys who irritated Robert on the drive to his villa, including Tony (Bobby Darin), set up camp right outside of the villa and begin courting the girls.
Robert chaperones the girls on a sightseeing tour and to a music club. He dances with each of the girls and appeals to their virtues, stressing the importance of chastity. Trying to get Robert inebriated, the boys end up drunk themselves. Sandy revives Tony, but slaps him when he makes a pass at her. She then recounts the lecture received earlier to Lisa, who gets infuriated over Robert's double standards. The next morning, she leaves to get back together with Spencer. A sobered-up Tony apologizes to Robert.
Accompanied by Maurice, Robert chases after Lisa, but she refuses to take him back. Maurice decides to play matchmaker, telling the police that his employer is a notorious criminal wanted in Rome. He also tells them that Lisa is his accomplice. His plan fails though. When it is all straightened out, Lisa returns to her apartment, where she finds Sandy. Hearing the teen's lament about lost love, she has an epiphany and leaves to take Robert back. On her way out, she meets Tony, whom she directs to her apartment, where he and Sandy reunite.
At the train station, Lisa borrows a toddler to convince the conductor that the father is abandoning them. Taken off the train, Robert reconciles with her. As a married couple, they return to the villa, which Maurice has turned into a hotel again, which is now occupied by a group of nuns.Rock Hudson as Robert L. Talbot
Gina Lollobrigida as Lisa Helena Fellini
Sandra Dee as Sandy Stevens
Bobby Darin as Tony
Walter Slezak as Maurice Clavell
Brenda De Banzie as Margaret Allison
Rosanna Rory as Anna
Ronald Howard as Spencer
Joel Grey as Beagle
Ronnie Haran as Sparrow
Chris Seitz as Larry
Cindy Conroy as Julia
Joan Freeman as Linda
Nancy Anderson as Patricia
Michael Eden as Ron
Claudia Brack as Carol
Screenwriters Stanley Shapiro and Maurice Richlin started working on the script in late 1959. While the film was in pre-production, Shapiro said in an interview: "I write all day at my office from 8:30 until 6:00, then have dinner and go home and spend two or three hours fixing, polishing or rewriting the day's output."
In early 1960, it was announced Rock Hudson and Gina Lollobrigida were set to star. Before Lollobrigida's participation was confirmed, Marilyn Monroe was rumored to be cast. Along with the cast revelations, it was immediately announced production was not set to start until later, because Hudson was still working on the film The Last Sunset (1961) and Lollobrigida had commitments to Go Naked in the World (1961) and Lady L (1965). In June 1960, Robert Mulligan signed on to the film's direction.
A month later, singer Bobby Darin was announced to make his film debut in Come September. He met Dee for the first time on location, fell in love and eventually married her. The making of Come September is portrayed in the Bobby Darin biopic Beyond the Sea (starring Kevin Spacey as Darin and Kate Bosworth as Dee).
Initially, Lollobrigida was reluctant because she was not enthusiastic about returning to Italy, where the film was shot. In an interview, she mentioned accepting the role because it allowed her to work with Hudson. Furthermore, she explained: "It's a comedy that can only be made in Italy."
Bobby Darin sings Multiplication and composed the Come September theme.
On Rotten Tomatoes, Come September has an 80% score based on five critic reviews.
There is an Indian Hindi remake titled Mere Sanam (1965) starring Asha Parekh.