Semigallia (; ) is one of the five multi-member constituencies of the Saeima, the national legislature of Latvia. The constituency was established in 1922 when the Saeima was established following Latvia's independence from the Soviet Union. It consists of the cities of Jēkabpils and Jelgava and municipalities of Aizkraukle, Aknīste, Auce, Bauska, Dobele, Engure, Iecava, Jaunjelgava, Jaunpils, Jēkabpils, Jelgava, Kandava, Koknese, Krustpils, Nereta, Ozolnieki, Pļaviņas, Rundāle, Sala, Skrīveri, Tērvete, Tukums, Vecumnieki and Viesīte in the region of Semigallia. The constituency currently elects 14 of the 100 members of the Saeima using the open party-list proportional representation electoral system. At the 2018 parliamentary election it had 213,068 registered electors.