Guaymas () is a city in Guaymas Municipality, in the southwest part of the state of Sonora, in northwestern Mexico. The city is 134 km south of the state capital of Hermosillo, and from the U.S. border. The municipality is located on the Gulf of California and the western edge of the Sonoran Desert and has a hot, dry climate and 117 km of beaches. The municipality's formal name is Guaymas de Zaragoza and the city's formal name is the Heróica Ciudad de Guaymas.