9th federal electoral district of Tamaulipas
The 9th federal electoral district of Tamaulipas (Spanish: Distrito electoral federal 09 de Tamaulipas) is a defunct federal electoral district of the Mexican state of Tamaulipas. It was in existence from 1978 to 1996 and again from 2017 to 2022.
During those periods, it returned one deputy to the Chamber of Deputies for each three-year legislative session by means of the first-past-the-post system. Votes cast in the district also counted towards the calculation of proportional representation ("plurinominal") deputies elected from the country's electoral regions.
The 9th district was first created as part of the 1977 electoral reforms, which increased the state's seat allocation from six to nine. Because of shifting population dynamics, it was subsequently abolished in 1996, re-established in 2017, and abolished again in 2023.