[2] The school district is named for its location in the northwestern area of the Dallas Fort Worth Metroplex.
The district serves the cities of Justin, Roanoke, Trophy Club, Northlake, Marshall Creek, Corral City, and small portions of Flower Mound and Southlake in Denton County.
The Wise County towns of Aurora, Rhome, Pecan Acres, Newark, and portions of New Fairview also lie within the district.
The Tarrant County portion of the district includes Haslet, Avondale, parts of Westlake, Keller, and Fort Worth.
Northwest ISD is expected to have up to 35,000 students by the early 2020s, and is the first fastest-growing school district in North Texas.