Leavenworth is a city in Chelan County, Washington, United States. It is part of the Wenatchee−East Wenatchee Metropolitan Statistical Area…Leavenworth is a city in Chelan County, Washington, United States. It is part of the Wenatchee−East Wenatchee Metropolitan Statistical Area. The population was 2,263 at the 2020 census. The entire town center is modeled on a German Bavarian village as part of a civic initiative that began in the 1960s.