Tochigi 3rd district (栃木[県第]3区 Tochigi[-ken dai-]san-ku) is a single-member electoral district for the House of Representatives, the lower house of the National Diet of Japan.

The only challenger the Democratic Party ever nominated has been Takashi Kobayashi in 2005.

In 2014 Watanabe was involved in a scandal over undisclosed loans[2] and lost the next elections to the LDP candidate Kazuo Yana.

Before the electoral reform, the area had been part of the five-member 1st district.

Representatives from the 1st district had included Watanabe's father Michio who died in 1995.