Sunday in New York is a 1963 American romantic comedy film directed by Peter Tewksbury from a screenplay by Norman Krasna, based on Krasna's 1961 play of the same name. Filmed in Metrocolor, the film stars Cliff Robertson, Jane Fonda, and Rod Taylor, with Robert Culp, Jo Morrow, and Jim Backus. The score was composed and recorded by Peter Nero, who also appears as himself performing in a nightclub; Mel Tormé sang the title song.

Eileen Tyler, a 22-year-old music critic for the Albany Times Union, is suffering from her breakup with Russ Wilson, a handsome, athletic, and thoroughly self-absorbed scion of Albany's richest family. Seeking advice on the premarital sex she has refused him, she appears unannounced at the chic Upper East Side loft apartment of her elder brother Adam, an airline pilot. Eileen confides to him that she thinks she may be the only 22-year-old virgin left in the world. Adam assures her that men want women who preserve their virtue, and, at her insistence, swears he has not slept around. An anxiously anticipated rendezvous with his occasional girlfriend Mona Harris, scuttled by Eileen's arrival, lets the audience know otherwise.

Shut out of his own apartment, Adam gamely tries to find a place for a tryst with Mona, ginning a cover story for Eileen that the pair are going skating at Rockefeller Center. Some time after their departure, Adam's boss rings up, desperate to locate an "on-call" pilot. Anxious to deliver the message to her brother, Eileen heads for the skating rink, only to begin a series of misadventures with a visiting Philadelphia music critic, Mike Mitchell.

These eventually lead the pair back to Adam's apartment to dry out rain-soaked clothes together. Scotch and some double-messaging from Eileen result in an outlandish attempt on her part to seduce a bewildered but ultimately game Mike—until he discovers she is a virgin. Invoking an unspoken code of honor among sexually active males, he refuses to take hers, much to Eileen's disorientation and annoyance. After cooling off, the bumptious and still semi-clad pair begin to calmly talk things through, only to be ambushed by the unannounced arrival of an obnoxiously giddy and hellfire marriage-bent Russ. Desperate to avoid being incriminated for something worse than had actually occurred, the pair pretends Mike is Adam, a ruse that comes off smoothly until Adam himself appears in his own doorway.

A modest farce devolves into a broad one, with an irritated Adam only scarcely willing to play his unwelcome part. Socked by him for even having tried to make love to his sister, Mike attempts an orderly retreat to Philadelphia while the ruse still holds, only to end up socked later outside the apartment by Russ after Eileen tried and failed to make a clean breast of things with her by-then fiance. Adam catches Mona on the telephone; he proposes and she says yes.

Soaked again, and with Adam apparently called away to fly, Mike ends up seeking dry refuge in Adam's apartment—once more, initially all on the up-and-up. He and Eileen retire separately. After believing he has locked her in the bedroom and literally thrown the key out the window, Mike confesses his love through the door. Met with dead silence, he retreats downstairs, only to have Eileen, who had meanwhile innocently slipped there, run into his arms.

A voiceover reveals Eileen ended up married and living happily in Tokyo with Mike, bearing the adoring couple three lovely daughters.

The play was seen on Broadway by Eliot Hyman and Ray Stark of Seven Arts Productions who "thought it would make a good movie", according to Stark. Other companies were interested in film rights, but Stark called Krasna direct in Switzerland and did the deal. According to one account, the rights cost $150,000 plus a percentage of the gross. Another account claims the price was $200,000.