The state of Ohio has 88 counties. The oldest county is Washington County, which was established in 1788, while the youngest county is Noble County, established in 1851.
The largest county in Ohio by population is Cuyahoga County, the home of Cleveland, which has a population of around 1.28 million people, as of the 2010 census. The smallest county by population is Vinton County, with a population of 13,435 people. The largest county by area is Ashtabula County, which has an area of 702.44 square miles for a population of 101,497 people. The smallest county is Lake County, with an area of 228.21 square miles.