Nagasaki 3rd district (長崎[県第]3区, Nagasaki[-ken dai-]sanku) is a single-member electoral district for the House of Representatives, the lower house of the National Diet of Japan. It is located in the prefecture of Nagasaki. It covers parts of Nagasaki on the main island of Kyūshū – the city of Ōmura and the towns of Kawatana, Hasami and Higashisonogi, Nagasaki in former Higashi-Sonogi ("East ") -gun (county or district) – and several of the prefecture's island municipalities: the cities of Iki, Tsushima and Gotō and the town of Shin-Kamigotō in Minami-Matsuura/"South " district. As of September 2011, 211,289 eligible voters were registered in Nagasaki 3rd district, giving it the second highest vote weight in the country.