Sonora y Sinaloa ("Sonora and Sinaloa") was one of the constituent states of the Mexican Republic under its Constitution of 1824. Whereas the federal constitution used the name "Sonora y Sinaloa", the state constitution, adopted on 31 October 1825, used the name Estado de Occidente ("State of the West").

The state capital was located at El Fuerte, Sinaloa. The first governor was the Sonoran Juan Miguel Riesgo.

On 30 September 1830, due to constant internal disputes, the state was divided into two – the states of Sonora and Sinaloa. While the territory of Sinaloa corresponds to that of the modern-day state of the same name, Sonora in the 1820s extended north over the current United States–Mexico border. Settlements only existed in the extreme south of the current State of Arizona and the northern frontier was not defined. Maps from the period will show the northern border as near today's international boarder or as far as either the Gila River or the Colorado River.

See also

• Territorial evolution of Mexico