Along with Callahan, Hilliard is one of the major economic centers in western Nassau County. Its location on the railroad and at the intersection of several major roads (US 1 and County Road 108) contributed significantly to economic growth. The area has important stands of wood used in papermaking, as well as wood products. Much of the tree growing area is owned by Rayonier or The Moyer Company.

Hilliard is home to a Federal Aviation Administration (FAA) Air Traffic Control Center, which coordinates most commercial and civil air traffic to the southeastern United States. The FAA center is a major employer in Hilliard and there are many retired FAA employees who live in the area and enjoy the relaxed rural lifestyle.

Hilliard is one of many towns along US 1 that saw its tourism trade dwindle when I-95 opened. Logging is an important industry in the area around Hilliard.

Because of the specific ground conditions and a large amount of open rural land in the area, Hilliard was considered by the Department of Energy as a possible location for the Superconducting Super Collider; however, this never came to fruition.