Richardson, TX has a population of 108,350 and is the 276th largest city in the United States. The population density is 3,793 per sq mi which is 3813% higher than the Texas average and 4087% higher than the national average. The median age in Richardson is 37 which is approximately 9% higher than the Texas average of 34. In Richardson, 61% of the population over 15 years of age are married, 68% speak English and 12% speak Spanish. 45% of Richardson residents were born in Texas, 29% were born out of state, 1% were born outside of the United States and 25% were foreign born.