Gruyère (UK: , US: , French: [ɡʁɥijɛʁ] (listen); German: Greyerzer) is a hard Swiss cheese that originated in the cantons of Fribourg, Vaud, Neuchâtel, Jura, and Berne in Switzerland. It is named after the town of Gruyères in Fribourg. In 2001, Gruyère gained the appellation d'origine contrôlée (AOC), which became the appellation d'origine protégée (AOP) as of 2013.

Gruyère is classified as a Swiss-type or Alpine cheese and is sweet but slightly salty, with a flavour that varies widely with age. It is often described as creamy and nutty when young, becoming more assertive, earthy, and complex as it matures. When fully aged (five months to a year), it tends to have small cracks that impart a slightly grainy texture. Unlike Emmental, with which it is often confused, modern Gruyère has few if any eyes, although in the 19th century, this was not always the case. It is the most popular Swiss cheese in Switzerland, and in most of Europe.