List of Interstate Highways in Texas

The Interstate Highways in Texas are all owned and maintained by the U.S. state of Texas. The Texas Department of Transportation (TxDOT) is the agency responsible for the day-to-day maintenance and operations of the Interstate Highways in Texas. The Interstate Highway System in Texas covers 3239.7 mi and consists of twelve primary routes, seven auxiliary routes and Interstate 35 (I-35) which is split into two branches, I-35E and I-35W, that provide access to both Fort Worth and Dallas. The longest segment of Interstate Highway in Texas is I-10 at 878.6 mi; the shortest is I-110 at 0.9 mi.

The construction of the Interstate Highway System in Texas began well before these routes were designated as Interstate Highways. A 50 mi stretch of 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. In 1962, 43 mi of I-35 opened in Bexar County, the first section of Interstate Highway to open from county line to county line in a large metropolitan area. Portions of I-10 west of San Antonio took much longer to complete due to the vast open spaces and lack of nearby labor. The majority of the construction of this section of I-10 occurred in the 1970s and 1980s and was complete by the early 1990s. The section east of San Antonio was completed 20 years earlier in 1972. The opening of a 6 mi section of I-27 in 1992 completed the Interstate Highway System in Texas.

Planning is ongoing for a proposed extension of I-69 southward from its original terminus in Indiana through Texas to the United States–Mexico border. If complete as planned, I-69 will extend about 650 mi across Texas, from the Louisiana state line in the Texarkana–Shreveport area to South Texas. The first 6.2 mi portion was approved in 2011, with signage posted December 6, 2011.