The Apartment was adapted into a Broadway musical, Promises, Promises, in 1968, book by Neil Simon, music by Burt Bachrach, lyrics by Hal David.

The tag line for the Tennessee Williams film Suddenly, Last Summer (1959) was "She knew she was being used for something evil." Wilder made a play on that line to promote The Apartment: "Suddenly, last winter - he knew his apartment was being used for something evil."

The theme from The Apartment, played by the piano duo Ferrante & Teicher, became a widely played radio hit.

by Rob Nixon