Peoria is a city in Maricopa and Yavapai counties in the U.S. state of Arizona. Most of the city is located in Maricopa County, while a portion of it in the north is in Yavapai County. It is a major suburb of Phoenix. As of the 2020 census, the population of Peoria was 190,985, up from 154,065 in 2010. It is the sixth-largest city in Arizona in land area and the ninth-largest in population. It was named after Peoria, Illinois.