The 21st federal electoral district of Mexico City (; 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.
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.
The current member for the district, elected in the 2024 general election, is José Carlos Acosta Ruiz of the National Regeneration Movement (Morena).
Under the 2023 districting plan adopted by the National Electoral Institute (INE), which is to be used for the 2024, 2027 and 2030 federal elections, the 21st district covers 136 electoral precincts () between the borough (alcaldÃÂa) of Milpa Alta and the bulk of Xochimilco (the north-western portion of that borough is assigned to the 5th district).
The district reported a population of 436,319 in the 2020 Census.
2017âÂÂ2022
2005âÂÂ2017
1996âÂÂ2005
1978âÂÂ1996