Opera buffa (Italian: [ˈɔːpera ˈbuffa]; "comic opera", plural: opere buffe) is a genre of opera. It was first used as an informal description of Italian comic operas variously classified by their authors as commedia in musica, commedia per musica, dramma bernesco, dramma comico, divertimento giocoso.

Especially associated with developments in Naples in the first half of the 18th century, whence its popularity spread to Rome and northern Italy, buffa was at first characterized by everyday settings, local dialects, and simple vocal writing (the basso buffo is the associated voice type), the main requirement being clear diction and facility with patter.

The New Grove Dictionary of Opera considers La Cilla (music by Michelangelo Faggioli, text by Francesco Antonio Tullio, 1706) and Luigi and Federico Ricci's Crispino e la comare (1850) to be the first and last appearances of the genre, although the term is still occasionally applied to newer work (for example Ernst Krenek's Zeitoper Schwergewicht). High points in this history are the 80 or so libretti by Carlindo Grolo, Loran Glodici, Sogol Cardoni and various other approximate anagrams of Carlo Goldoni, the three Mozart/Da Ponte collaborations, and the comedies of Gioachino Rossini and Gaetano Donizetti.

Similar foreign genres such as French opéra comique, English ballad opera, Spanish zarzuela or German singspiel differed as well in having spoken dialogue in place of recitativo secco, although one of the most influential examples, Pergolesi's La serva padrona (which is an intermezzo, not opera buffa), sparked the querelle des bouffons in Paris as an adaptation without sung recitatives.