The ninth federal electoral district of Chiapas (Distrito electoral federal 09 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 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 third region.[1][2]
The ninth district was established as part of the 1977 electoral reforms. Under the 1975 districting plan, Chiapas had only six congressional districts;[3] under the 1977 reforms, the number increased to nine.[4] The newly created ninth district elected its first deputy, to the 51st Congress, in the 1979 mid-term election.