Successful British box manufacturer Charlie Blake (Anthony Newley) meets Sara Deever (Sandy Dennis) when they both take a driver's exam in New York City. She tries to get a few answers from him, but he gets expelled for cheating. They run into each other later and go out on a date.

When they return to her apartment, Charlie meets Alonzo (Theodore Bikel), Sara's older, vegetarian friend. Then Richard (Sandy Baron) bursts in; he begs her to let him stay with her, but she has already packed his bag. After he leaves, Charlie asks her why Richard referred to him as his successor. She explains that she has a "special therapy program": She takes in a man for no longer than a month to diagnose and fix whatever problem he has. Richard was October, and she wants him to be November. She believes his trouble is his devotion to his work. Charlie accepts, though he is only interested in a short fling. He tells his employee, Digby (King Moody), to send him a telegram after a week so he will have an excuse to leave.

As November progresses, however, Charlie begins to fall in love (for the first time in his life) with the unorthodox Sara. When he gets the prearranged telegram, he telephones Digby to tell him to handle an important business meeting by himself. Clem Batchman (Burr DeBenning), another of Sara's projects, shows up, inciting Charlie's jealousy, until Sara informs him that he just wants to introduce her to his fiancée, Carol (Marj Dusay).

Charlie becomes troubled by certain signs that Sara may be ill. When he asks Alonzo, his worst fears are confirmed: Sara has only a little time left. She lives as she does so that she will be remembered after she is gone. Charlie tries hard to get her to break her self-imposed rule, and believes he has succeeded. She later admits to Alonzo that, unlike all the others, she has fallen for Charlie, but wants him to remember her as she is now. Thus, when December (and a clumsy Gordon) arrives, she has secretly packed November's bag. Charlie reluctantly leaves, promising he will never forget her.

• Sandy Dennis as Sara Deever
• Anthony Newley as Charlie Blake
• Theodore Bikel as Alonzo
• Burr DeBenning as Clem Batchman
• Sandy Baron as Richard
• Marj Dusay as Carol
• Martin West as Gordon
• Virginia Vincent as Mrs. Schumacher
• King Moody as Digby
• Robert Gibbons as Sam Naylor

Audrey Hepburn originally was announced for the lead.^[3]

In her February 9, 1968 review for The New York Times, Renata Adler writes “Sweet November must be the most sentimental and sinister fantasy about contemporary love in years. One can't help leaving the theater sniffling and furious with oneself, which makes the movie a little hard to criticize. When Radio City Music Hall, runs a movie about a girl—not a siren or a villainess, but a nice, fairly ordinary girl — who takes a different lover every month, there must be something very serious going on. And there is. A new myth that is deep and probably durable. …(reversing) the terms of the modern urban argument: he wants to get married, and she, for her own special reasons, wants to have an affair. …There is only one possible resolution for all this perfection. True romantics have always seen it, and the 'movie quite mawkishly presents it. Tragedy attends promiscuity at the Music Hall, still.Sandy Dennis is very good. … Anthony Newley, hardly clowning at all and playing quite softly, is good, too. Theodore Bikel, as a kind of vegetarian friend of the family, has to handle most of the mawkish part, and there is not much he can do with it. The music by Michel Legrand (who did "Umbrellas of Cherbourg"), is not very noticeable—except for one song, "Sweet November," .. which is ghastly. The dialogue, by Herman Raucher, is extremely solid and witty. …Unfortunately, Newley is supposed to be afflicted in the picture with a neurotic sense of haste that everyone keeps referring to as "Hurry, hurry, ding, ding." This is even more annoying than it sounds.But despite all the sick, dreadful assumptions about life that turn out to underlie the plot—and as you think about it after you've seen it, you'll probably be appalled—"Sweet November" succeeds.^[4]

On March 22, 2009, the film was released on DVD by Warner Bros.

• Sweet November at IMDb  
• Sweet November at the TCM Movie Database
• Sweet November at AllMovie
• Sweet November at the American Film Institute Catalog