Harlingen, TX has a population of 65,634 and is the 569th largest city in the United States. The population density is 1,640 per sq mi which is 1591% higher than the Texas average and 1710% higher than the national average. The median age in Harlingen is 31 which is approximately 9% lower than the Texas average of 34. In Harlingen, 56% of the population over 15 years of age are married, 48% speak English and 51% speak Spanish. 72% of Harlingen residents were born in Texas, 13% were born out of state, 1% were born outside of the United States and 14% were foreign born.