U.S. Route 83 (US 83) is a major north–south United States Numbered Highway that extends 1,885 miles (3,034 km) in the central United States. Only four other north–south routes are longer: US 1, US 41, US 59, and US 87, while US 83 follows a straighter north-south path than all of these. Nearly half of its mileage is in the state of Texas. The highway's northern terminus is north of Westhope, North Dakota, at the Canadian border, where it continues as Manitoba Highway 83 (PTH 83). The southern terminus is at the Veterans International Bridge in Brownsville, Texas. Together, US 83 and PTH 83 form a continuously numbered north-south highway with a combined distance of 3,450 kilometres (2,140 mi).

Harlingen is a city in Cameron County in the central region of the Rio Grande Valley of the southern part of the U.S. state of Texas, about 30 miles (48 km) from the coast of the Gulf of Mexico. The city covers more than 40 square miles (104 km2) and is the second-largest city in Cameron County, as well as the fourth-largest in the Rio Grande Valley. As of the 2020 census, the city had a population of 71,892.