San Tan Valley, AZ has a population of 88,507 and is the 367th largest city in the United States. The population density is 2,413 per sq mi which is 4098% higher than the Arizona average and 2564% higher than the national average. The median age in San Tan Valley is 32 which is approximately 15% lower than the Arizona average of 37. In San Tan Valley, 59% of the population over 15 years of age are married, 86% speak English and 11% speak Spanish. 39% of San Tan Valley residents were born in Arizona, 52% were born out of state, 1% were born outside of the United States and 8% were foreign born.