Twelfth federal electoral district of Chiapas

The twelfth federal electoral district of Chiapas (Distrito electoral federal 12 de Chiapas) is one of the 300 electoral districts into which Mexico is divided for elections to the federal Chamber of Deputies and one of 13 such districts in the state of Chiapas.

It elects one deputy to the lower house of Congress for each three-year legislative period, by means of the first-past-the-post system. Votes cast in this district also count towards the calculation of proportional representation ("plurinominal") deputies elected from the third region.

The twelfth district of Chiapas was created in 1996. Between 1979 and 1996, the state had only nine congressional districts; the 1996 redistricting process increased the number to 12. The three new districts elected their first deputies, to the 57th Congress, in the 1997 mid-terms.

District territory
Under the 2022 districting plan, which will be used for the 2024, 2027 and 2030 federal elections, the 12th district comprises seven municipalities in the extreme south of the state: The district's head town (cabecera distrital), where results from individual polling stations are gathered together and collated, is the city of Tapachula.
 * Cacahoatán, Frontera Hidalgo, Metapa, Suchiate, Tapachula, Tuxtla Chico and Unión Juárez.

Previous districting schemes
From 2017 to 2022 the district had same composition as in the 2017 plan.
 * 2017–2022

The district was located in the same basic region but comprised the municipalities of Frontera Hidalgo, Metapa, Suchiate, Tuxtla Chico and three-quarters of the municipality of Tapachula (the northern quarter was in the 11th district). The district's head town was the city of Tapachula.
 * 2005–2017

Between 1996 and 2005, the district had a different configuration: it covered the municipality of Tapachula in its entirety, together with Cacahoatán and Unión Juárez, in addition to the others that it covered between 2005 and 2017.
 * 1996–2005