The 18th federal electoral district of Mexico City (Distrito electoral federal 18 de la Ciudad de México; prior to 2016, "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] Under the National Electoral Institute's 2022 districting plan, which will be used for the 2024, 2027 and 2030 federal elections,[4] the 18th district covers the central portion of the borough (alcaldía) of Iztapalapa.

[5][1] Under the 2005 districting scheme, the 18th district covered the northern portion of the borough (delegación) of Iztapalapa.