Hendecasyllable verse (in Italian endecasillabo) is a kind of verse used mostly in Italian poetry, defined by its having the last stress on the tenth syllable. When, as often happens, this stress falls on the penultimate syllable, the line has exactly eleven syllables (and the literal meaning of the word is just "of eleven syllables").

The most usual stress schemes for an hendecasyllable are stresses on 6th and 10th syllables ("Nel mezzo del cammin di nostra vita," Dante Alighieri, first line of The Divine Comedy), and on 4th, 7th and 10th syllables ("Un incalzar di cavalli accorrenti," Ugo Foscolo, I Sepolcri).

Most classical Italian poems are composed of hendecasyllables, for instance, the main works by Dante, Francesco Petrarca, Ludovico Ariosto, and Torquato Tasso.

It has a role in Italian poetry, and a formal structure, comparable to the iambic pentameter in English or the alexandrine in French.

This form is not to be confused with hendecasyllabics, a quantitative meter used by Catullus.