Alcona County is a county of the U.S. state of Michigan. As of the 2020 census, the population was 10,167. Its county seat is Harrisville. Alphabetically it is the first county in Michigan; as its flag states, it is the "First of 83".

Harrisville is a city in the U.S. state of Michigan and the county seat of Alcona County. The population was 437 at the 2020 census, making Harrisville the sixth-smallest city by population in the state of Michigan. The city is surrounded by Harrisville Township but is administratively autonomous. Located on Lake Huron, it is an official Michigan Department of Natural Resources Harbor of Refuge.