Nasu District, Tochigi

 is a district located in Tochigi Prefecture, Japan. The district consists of the two discontiguous towns of Nasu and Nakagawa, separated by the city of Ōtawara in the middle.
The total area of the district was 1,209.59 km2 before the former constituent towns of Nishinasuno, and Shiobara were consolidated with Kuroiso to form the new city of Nasushiobara on January 1, 2005. In 2003, the district had an estimated population of 154,881 and a density of 128.04 persons per km2.