Ohio /oʊˈhaɪ.oʊ/ is a state in the midwestern region of the United States. Ohio is the 34th largest by area, the 7th most populous, and the 10th most densely populated of the 50 United States. The state's capital and largest city is Columbus.

The state takes its name from the Ohio River. The name originated from the Iroquois word ohi-yo’, meaning "great river" or "large creek." Partitioned from the Northwest Territory, the state was admitted to the Union as the 17th state (and the first under the Northwest Ordinance) on March 1, 1803. Ohio is historically known as the "Buckeye State" after its Ohio buckeye trees, and Ohioans are also known as "Buckeyes."