Navojoa is the fifth-largest city in the northern Mexican state of Sonora and is situated in the southern part of the state. The city is the administrative seat of Navojoa Municipality, located in the Mayo River Valley.
The city name derives from the native Mayo language meaning "Cactus House" or "Cactus Place" ("Navo"= Cactus, "Jova"= House). The valley has been continuously inhabited since pre-Hispanic times by the Mayo people.
In September 1536, Diego de Guzmán, a Spaniard, became the first known European to reach the valley and the first Jesuit missionaries started settling in the region in 1614. Several geoglyphs from the Mayo tribe can be found along the Mayo River.