Casa Grande (käˈsä gränˈdā) [key], city (1990 pop. 19,082), Pinal co., S Ariz.; inc. 1915. It lies in an irrigated farm area near the Casa Grande Mts. The city was named after an excavated pueblo that is included in the nearby Casa Grande National Monument (see National Parks and Monuments, table). Casa Grande is a retail trade center of S central Arizona.