Zarzuela (Spanish pronunciation: [θaɾˈθwela]) is a Spanish lyric-dramatic genre that alternates between spoken and sung scenes, the latter incorporating operatic and popular songs, as well as dance. The etymology of the name is uncertain, but some propose it may derive from the name of a royal hunting lodge, the Palace of Zarzuela, near Madrid, where that type of entertainment was allegedly first presented to the court. The palace in turn was named after the brambles (zarzas) that grew there.

There are two main forms of zarzuela: Baroque zarzuela (c. 1630–1750), the earliest style, and Romantic zarzuela (c. 1850–1950). Romantic zarzuelas can be further divided into two main subgenres, género grande and género chico, although other sub-divisions exist.

Zarzuela spread to the Spanish dominions, and many Spanish-speaking countries – notably Cuba – developed their own traditions. Zarzuela is also a strong tradition in the Philippines, where it is also referred to in certain languages as sarswela/sarsuela. Other regional and linguistic variants in Spain include the Basque zartzuela and the Catalan sarsuela.

A masque-like musical theatre had existed in Spain since the time of Juan del Encina. The zarzuela genre was innovative in giving a dramatic function to the musical numbers, which were integrated into the plot of the work. Dances and choruses were incorporated as well as solo and ensemble numbers, all to orchestral accompaniment.