The Barber of Seville, or The Useless Precaution (Italian: Il barbiere di Siviglia, ossia L'inutile precauzione [il barˈbjɛːre di siˈviʎʎa osˈsiːa liˈnuːtile prekautˈtsjoːne]) is an opera buffa in two acts composed by Gioachino Rossini with an Italian libretto by Cesare Sterbini. The libretto was based on Pierre Beaumarchais's French comedy The Barber of Seville (1775). The première of Rossini's opera (under the title Almaviva, o sia L'inutile precauzione) took place on 20 February 1816 at the Teatro Argentina, Rome, with designs by Angelo Toselli.

Rossini's Barber of Seville has proven to be one of the greatest masterpieces of comedy within music, and has been described as the opera buffa of all "opere buffe". After two hundred years, it remains a popular work.