Peoria, AZ has a population of 158,677 and is the 159th largest city in the United States. The population density is 903 per sq mi which is 1471% higher than the Arizona average and 897% higher than the national average. The median age in Peoria is 39 which is approximately 6% higher than the Arizona average of 37. In Peoria, 58% of the population over 15 years of age are married, 85% speak English and 10% speak Spanish. 40% of Peoria residents were born in Arizona, 50% were born out of state, 1% were born outside of the United States and 9% were foreign born.