Lake County is a county in the U.S. state of Ohio. As of the 2020 census, the population was 232,603. Its county seat is Painesville, and its largest city is Mentor.

Painesville is a city in and the county seat of Lake County, Ohio, United States, located along the Grand River 27 miles (43 km) It is a northeast suburb of Cleveland. Its population was 20,312 at the 2020 census. Painesville is part of the Greater Cleveland Metropolitan Area and is included in the Cleveland-Akron-Canton, Ohio Consolidated Metropolitan Statistical Area.