Minnetonka Beach is a city in Hennepin County, Minnesota, United States. Located on Lake Minnetonka, the population was 539 at the 2010 ce…Minnetonka Beach is a city in Hennepin County, Minnesota, United States. Located on Lake Minnetonka, the population was 539 at the 2010 census. Minnetonka Beach is located on the shores of Lake Minnetonka. Originally part of Excelsior Township, Minnetonka Beach was the site of the Hotel Lafayette, which was built by the Minneapolis, Saint Paul, & Manitoba Railway in 1882. In 1884, Minnetonka Beach was annexed by Medina Township. The community was incorporated as an independent village in 1894.