Ottawa County is a county located in the U.S. state of Michigan. As of the United States 2020 Census, the population was 296,200. The county seat is Grand Haven. The county is named for the Ottawa Nation, was set off in 1831 and organized in 1837. Ottawa County is included in the Grand Rapids-Kentwood, MI Metropolitan Statistical Area and has a significant Dutch American population.

Grand Haven is a city within the U.S. state of Michigan and the county seat of Ottawa County. Grand Haven is located on the eastern shore of Lake Michigan at the mouth of the Grand River, for which it is named. As of the 2010 census, Grand Haven had a population of 10,412. The city is home to the Grand Haven Memorial Airpark (3GM) and is located just north of Grand Haven Charter Township.