The City of Wasilla is a city in Matanuska-Susitna Borough, United States and the fourth-largest city in Alaska. It is located on the northern point of Cook Inlet in the Matanuska-Susitna Valley of the southcentral part of the state. The city's population was 9,054 at the 2020 census, up from 7,831 in 2010. Wasilla is the largest city in the borough and a part of the Anchorage metropolitan area, which had an estimated population of 398,328 in 2020.