The Interstate Highways in Texas cover 3,233.4 miles (5,203.7 km) in the state. The freeways are maintained by the Texas Department of Transportation (TxDOT) as the state agency responsible for all state highways, including the Interstate Highways in Texas. There are nine primary routes, six auxiliary routes and the two branches of Interstate 35 (I-35) into I-35E and I-35W, that provide access to both Fort Worth and Dallas. The Interstate Highway with the longest segment in Texas is I-10 at 878.6 miles (1,414.0 km). The shortest Interstate Highway in the state is I-110 at 0.9 miles (1.4 km).

The construction of the Interstate Highway System in Texas actually began well before these routes were designated as Interstate Highways. A 50-mile (80 km) stretch of the Gulf Freeway ( I-45) between Galveston and Houston was opened in 1951, eight years before it was designated I-45; it was also the first urban expressway in Texas. The opening of a 6-mile (10 km) section of I-27 in 1992 completed the system. Planning is ongoing for a proposed extension of I-69 southward from its current terminus in Indiana through Texas to the Mexico–United States border. If built, I-69 will extend about 650 miles (1,050 km) across Texas, from the Louisiana state line in the Texarkana– Shreveport area to South Texas.

Recently selected: Mississippi Highway 172 • Interstate 235 • U.S. Route 113