Peoria is a city in Maricopa and Yavapai counties in the U.S. state of Arizona. Located primarily in Maricopa County, it is a major suburb of Phoenix. According to 2010 Census Bureau releases, the population of the city is 154,065. Peoria is currently the sixth largest city in Arizona for land area, and the ninth largest for population. It was named after Peoria, Illinois. (The word peoria is a corruption of the Illini word for “prairie fire”.