C. C. Baxter's (Jack Lemmon) office building – 2 Broadway, New York, New York. The 32-story skyscraper, completed in 1959 right before the filming, replaced a landmark of the nineteenth-century city, George B. Post's New York Produce Exchange. The curtain wall was redesigned in 1999.
Baxter’s apartment – 55 W 69th Street, New York, New York. There are a few shots of the real building but the rest was done on a soundstage replica. The façade has since changed and the staircases have been removed. What used to be the apartment entrance is now a second-story window.
However, when he looks up at his apartment windows it's actually 51 W 69th Street!
Baxter spends a night on a park bench – West Drive, Central Park, New York, New York.
Baxter makes a date with Fran Kubelik (Shirley MacLaine) – Beaver Street at Broadway, New York, New York.
Fran goes to a Chinese restaurant – New Street, New York, New York.
The Chinese restaurant where Fran meets with Baxter's boss Sheldrake (Fred MacMurray) – 58 or 60 New Street, New York, New York. It has since been replaced with a modern building, and it’s hard to pinpoint the exact address.
Baxter waiting for Ms Kubelik outside the theater – The Majestic, 245 W 44th Street, New York, New York. The marquee advertises The Music Man, "one of the best musical comedies of our times." The times have surely changed, and it's showing The Phantom of the Opera now.