Oh, OH or Oh! is an interjection, proclaiming surprise. It may refer to:
Ohio is a Midwestern state in the Great Lakes 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 Ohio State University, commonly referred to as Ohio State or OSU, is a large, primarily residential, public university in Columbus, Ohio.
Ohio University is a large, primarily residential, public research university in Athens, Ohio, United States.
Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points.
Ohio Wesleyan University (also known as Wesleyan or OWU) is a private liberal arts college in Delaware, Ohio, United States.
The Ohio River, which streams westward from Pittsburgh, Pennsylvania, to Cairo, Illinois, is the largest tributary, by volume, of the Mississippi River in the United States.
The Ohlone, named Costanoan by early Spanish colonists (the Spanish word costa means "coast"), are a Native American people of the Northern California coast.