Kagoshima 3rd district (鹿児島[県第]3区 Kagoshima[-ken dai-]san-ku) is a single-member constituency of the House of Representatives in the Diet of Japan. It is located in Western Kagoshima and consists of the cities of Satsumasendai, Makurazaki, Ichikikushikino, Hioki, Minamisatsuma, Minamikyūshū (without the former town of Ei), the former towns of Kōriyama and Matsumoto in the current city of Kagoshima and the town of Satsuma in Satsuma county. As of 2009, 265,049 eligible voters were registered in the district.
Before the electoral reform of 1994, the area was split between the multi-member districts Kagoshima 1 that elected four Representatives by single non-transferable vote and Kagoshima 2 with three representatives.
After its creation, the new 3rd district was initially a solid "conservative kingdom", a safe seat for the Liberal Democratic Party. Its first representative Tadahiro Matsushita (Obuchi faction, pre-reform: 2nd district) was followed by Kazuaki Miyaji (Mitsuzuka faction, pre-reform: 1st district) in 2000. Matsushita became a representative for the Kyūshū proportional representation block. In the "postal Diet" of 2005, he was a postal privatization rebel and tried to retake Kagoshima 3rd district as an independent in the ensuing snap election but lost to Miyaji. After initially declaring his retirement from politics, Matsushita returned in 2009 as a candidate for the People's New Party with Democratic support and won the district against Miyaji. After Matsushita's suicide in 2012, Miyaji won the resulting by-election against government candidate Takeshi Noma. In the general House of Representatives election less than three months later, Miyaji lost the district to Noma.