The Old San Antonio Road was a historic roadway located in the U.S. states of Texas and Louisiana. Parts of it were based on traditional Native American trails. Its Texas terminus was about 35 miles (56 km) southeast of Eagle Pass at the Rio Grande in Maverick County, and its northern terminus was at Natchitoches, Louisiana. The road continued from Texas through Monclova to Mexico City.
The Old San Antonio Road is considered a part of El Camino Real de los Tejas National Historic Trail.