Sinaloa is bordered to the north by Sonora and Chihuahua; to the south, by Nayarit; to the east by Durango, and to the west, across the Gulf of California, Baja California Sur. The eighteen municipios of Sinaloa are home to approximately 2,425,675 inhabitants. The coastal plain is a narrow strip of land that stretches along the length of the state and lies between the ocean and the foothills of the Sierra Madre Occidental Range, which dominates the eastern part of the state. Sinaloa is traversed by many rivers, which carve broad valleys into the foothills. The largest of these rivers are the Culiacan, Fuerte, and Sinaloa.

Culturally, it is known for a style of music known as banda, and corrido is also popular. It is the only place in the continent where the ancient ball game of Mesoamerica is still played, in a handful of small, rural communities not far from Mazatlan.