San Juan, TX has a population of 35,983 and is the 1,171st largest city in the United States. The population density is 3,097 per sq mi which is 3094% higher than the Texas average and 3318% higher than the national average. The median age in San Juan is 30 which is approximately 14% lower than the Texas average of 34. In San Juan, 59% of the population over 15 years of age are married, 11% speak English and 89% speak Spanish. 64% of San Juan residents were born in Texas, 6% were born out of state, 1% were born outside of the United States and 29% were foreign born.