Mississippi Highway 304 consists of two routes in northwest Mississippi:

MS 304 formerly ran on a two-lane alignment south of the present routing from U.S. 61 in Tunica Resorts (Tunica County) east to Interstate 55 in Hernando. The western portion of the former route is now officially part of MS 713; the remainder of the route (except the portion that is part of the scenic route noted above) no longer has an official state designation, but a number of state highway markers still appear along the route and at intersections.

East of Hernando, the proposed route of MS 304 coincides with proposed Interstate 269, continuing east to enter Marshall County near Byhalia to intersect U.S. Highway 78 (future Interstate 22), then turning north to cross the Mississippi–Tennessee border near Piperton. Tennessee would construct the remainder of the route north to existing TN 385. This portion of the route is currently in the planning stages, with construction expected to begin around 2009.