Yamagata 1st district (山形県第1区, Yamagata-ken dai-ikku or simply 山形県第1区, Yamagata-ikku) is a single-member constituency of the House of Representatives in the Diet of Japan. It is located in Eastern Yamagata and covers the cities of Yamagata, Kaminoyama and Tendō and the county of Higashimurayama. As of 2012, 306,446 eligible voters were registered in the district.