State Highway 16 is a south–north state highway in the U.S. state of Texas that runs from Zapata on the boundary with Mexico to U.S. Highway 281 24 miles (39 km) south of Wichita Falls. It is the longest state highway in Texas at almost 542 miles (872 km), but is only the ninth-longest of any highway classification in the state.

Zapata is a census-designated place (CDP) in and the county seat of Zapata County, Texas, United States. The population was 5,089 at the 2010 census. As an unincorporated community, Zapata has no municipal government, but like all 254 Texas counties has four elected county commissioners chosen by single-member districts and a countywide elected administrative judge.