Fanuj District () is a former administrative division of Nik Shahr County, Sistan and Baluchestan province, Iran. Its capital was the city of Fanuj.
After the 2011 National Census, the district was separated from the county in the establishment of Fanuj County.
At the time of the 2006 census, the district's population was 38,459 in 8,450 households. The following census in 2011 counted 45,637 people in 10,979 households.