The fourth federal electoral district of Sonora (Distrito electoral federal 04 de Sonora) is one of the 300 electoral districts into which Mexico is divided for elections to the federal Chamber of Deputies and one of seven such districts in the state of Sonora.[1]
It elects one deputy to the lower house of Congress for each three-year legislative session by means of the first-past-the-post system. Votes cast in the district also count towards the calculation of proportional representation ("plurinominal") deputies elected from the first region.[2][3]