11 o'clock number is a theatre term for a big, show-stopping song that occurs late in the second act of a two-act musical, in which a major character, often the protagonist, comes to an important realization. Examples include "So Long Dearie" from Hello, Dolly!, "Rose's Turn" from Gypsy, and "Work the Wound" from Passing Strange.^[1] It was so named because in the days when musical performances would start at 8:30 pm, this song would occur around 11:00 pm.^[2]

Among the theatre community, there is some debate as to the characteristics of an 11 o'clock number. It often signifies a moment of revelation or change in heart of a lead character, although there are exceptions to this.^[3] The 11 o'clock number is also differentiated from the finale in that it is not the final number in the show, but even this is not considered a requirement by some commenters.^[4] Broadway producer Jack Viertel defines an 11 o'clock number as "a final star turn".^[5]

Other notable 11 o'clock numbers include "Sit Down, You're Rockin' the Boat" from Guys and Dolls,^[3] "Memory" from Cats,^[6] "Brotherhood of Man" from How to Succeed in Business Without Really Trying,^[7] "Gimme Gimme" from Thoroughly Modern Millie,^[4] "Another National Anthem" from Assassins,^[8] "The American Dream" from Miss Saigon, "I'm Here" from The Color Purple,^[9] and "Always Starting Over" from If/Then.^[10]