Nagasaki 3rd district (長崎[県第]3区, Nagasaki[-ken dai-]sanku) is a single-member electoral district of the Japanese House of Representatives, the lower house of the National Diet.

Before the electoral reform of 1994, the area had formed part of the four-member Nagasaki 2nd district.

Tanigawa regained the seat in 2012, and held it until he resigned in 2024 due to his involvement in the 2023–2024 Japanese slush fund scandal.

[2] In September 2011, 211,289 eligible voters were registered in Nagasaki 3rd district, giving it the second highest vote weight in the country.

[3] Due to reapportionment, Nagasaki lost one seat in 2022 and the boundaries of the district changed significantly.