The ninth federal electoral district of Mexico City (Distrito electoral federal 09 de la Ciudad de México; previously "of the Federal District") is one of the 300 electoral districts into which Mexico is divided for elections to the federal Chamber of Deputies and one of the 22 currently operational districts in Mexico City.[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 fourth region.[2][3]