Ozaukee County is a county in the U.S. state of Wisconsin. As of the 2020 census, the population was 91,503. Its county seat is Port Washington. Ozaukee County is included in the Milwaukee–Waukesha–West Allis, WI Metropolitan Statistical Area. As of the 2000 Census, Ozaukee County had the second-lowest poverty rate of any county in the United States, at 2.6%. In terms of per capita income, it is the 25th-wealthiest county in the country.