"Last Night When We Were Young" is a 1935 popular song composed by Harold Arlen, with lyrics by Yip Harburg. Arlen regarded it as the favourite of the songs that he had written.
Lawrence Tibbett recorded the song on October 9, 1935. It was cut from his film Metropolitan but performed instrumentally behind the credits.
"Last Night When We Were Young" was highly regarded by Judy Garland, who recorded it twice, and frequently performed it. Composer Alec Wilder called it a "most remarkable and beautiful song" that "goes far beyond the boundaries of popular music." Continuing, he stated that "[i]t is unlike any other Arlen song that I have heard. However, it is unmistakably his." Harburg did not know where he acquired the title, saying, "the juxtaposition of those two phrases is almost a whole world of philosophy".