
Peoria is a city in Maricopa and Yavapai counties in the state of Arizona. Most of the city is located in Maricopa County, while a portion 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 currently the sixth-largest city in Arizona in land area and the ninth-largest in population. It was named after Peoria, Illinois. The word Peoria is a corruption of the Miami-Illinois word for "prairie fire". It is the spring training home of the San Diego Padres and Seattle Mariners, who share the Peoria Sports Complex.
The city is bordered to the east by Phoenix, to the southeast and south by Glendale, to the southwest by Youngtown and unincorporated Sun City, and to the west by Surprise. According to the United States Census Bureau, the city has a total area of 179.2 square miles, of which 176.1 square miles are land and 3.2 square miles, or 1.77%, are water. The water area is due to Lake Pleasant, a reservoir on the Agua Fria River in the northern part of the city.