"Istanbul (Not Constantinople)" is a 1953 novelty song, with lyrics by Jimmy Kennedy and music by Nat Simon. It was written on the 500th anniversary of the fall of Constantinople to the Ottomans. The lyrics humorously refer to the official renaming of the city of Constantinople to Istanbul. The song's original release, performed by The Four Lads, was certified as a gold record. Numerous cover versions have been recorded over the years, most famously a 1990 rock version by They Might Be Giants.

The Four Lads were a Canadian male singing quartet that earned many gold singles and albums in the 1950s, 1960s, and 1970s. Their million-selling signature tunes include "Moments to Remember"; "Standing on the Corner"; "No, Not Much"; "Who Needs You?" and "Istanbul".