Fifth federal electoral district of Sonora

The fifth federal electoral district of Sonora (Distrito electoral federal 05 de Sonora) is one of the 300 electoral districts into which Mexico is divided for elections to the federal Chamber of Deputies and one of seven such districts in the state of Sonora.

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 first region.

The 5th district was created in 1978 and was first contested in the 1979 legislative election.

District territory
Under the 2022 districting plan, which will be used for the 2024, 2027 and 2030 federal elections, Sonora's fifth district covers the south-eastern half of the municipality of Hermosillo. The district's head town (cabecera distrital), where results from individual polling stations are gathered together and collated, is the state capital, the city of Hermosillo.

Previous districting schemes
Between 2017 and 2022, the district had the same configuration as at present.
 * 2017–2022

In the 1996 and 2005 districting plans, the district covered the southern and eastern parts of the municipality of Hermosillo, albeit with adjustments to the dividing line with the remainder of the municipality belonging to the third district under the different schemes.
 * 1996–2017

The districting scheme in force from 1978 to 1996 was the result of the 1977 electoral reforms, which increased the number of single-member seats in the Chamber of Deputies from 196 to 300. Under that plan, Sonora's seat allocation rose from four to seven. The newly created 5th district had its head town at San Luis Río Colorado and it covered 14 municipalities in the state's north-west: Altar, Atil, Benjamín Hill, Caborca, Carbó, Opodepe, Oquitoa, Pitiquito, Puerto Peñasco, San Luis Río Colorado, Santa Ana, Sáric, Trincheras and Tubutama.
 * 1978–1996