The City of Peoria was established in the 1880's when William J. Murphy's vision of fertile farm lands fed by water from the Salt River became reality with the completion of the Arizona Canal in 1885. Once this canal was completed, Murphy went East to interest people in settling in this new community. Mr. Murphy was successful in catching people's attention – over 5,000 acres of land in the new district was purchased by citizens from Peoria, Illinois. Four families from Peoria, Illinois were among the first to move to Arizona to occupy and work their land.

Peoria was incorporated in 1954, with boundaries covering one square mile of land. The warm climate and small-town atmosphere of Peoria continued to attract people, and still do today. Currently, Peoria covers 162 square miles, and is home to over 120,000 residents. Peoria is Arizona's 4th largest city in terms of incorporated area, and 9th largest city in terms of population.