The güiro (Spanish pronunciation: [ˈɡwiɾo]) is a percussion instrument consisting of an open-ended, hollow gourd with parallel notches cut in one side. It is played by rubbing a stick or tines (see photo) along the notches to produce a ratchet sound.

The güiro is commonly used in Cuban, Puerto Rican, and other forms of Latin American music, and plays a key role in the typical rhythm section of important genres like son, trova and salsa. Playing the güiro usually requires both long and short sounds, made by scraping up and down in long or short strokes.

The güiro, like the maracas, is often played by a singer. It is closely related to the Cuban guayo, Dominican güira, and Haitian graj which are made of metal. Other instruments similar to the güiro are the Colombian guacharaca, the Brazilian reco-reco, the quijada (cow jawbone) and the frottoir (French) or fwotwa (French Creole) (washboard).