Ohio is unusual in having the only state flag that is not rectangular. Based on the Cavalry Guidon carried during the Civil War, the pennant shaped flag displays a modified version of the stars and stripes. The shape is a tapered burgee.

The seventeen stars refer to Ohio's position as the seventeenth state to join the United States. Ohio entered the Union March 1, 1803.

The red circle represents the Buckeye, the Ohio state tree, surrounding the Buckeye is a white O, this is for OHIO. The blue triangle represents the hills and the valleys. The red and white stripes signify the Ohio's rivers and highways. The top, middle and bottom stripes are red, the other two are white.

The flag flew for the first time over the Ohio Building at the 1901Pan-American Exposition in Buffalo, New York.

The flag was designed by John Eisenmann in 1901. The Ohio legislature adopted the flag May 9, 1902

The seal illustrates Ohio's diverse geography. In the background stands Mount Logan in Ross County. Separating Mount Logan from the rest of the seal is the Scioto River. In the foreground is a freshly harvested wheat field. In the field stands a sheaf of wheat, illustrating the importance of agriculture in Ohio. Nearby stand seventeen arrows that resemble the sheaf of wheat. The seventeen arrows represent Ohio's Native Americans as well as the fact that Ohio was the seventeenth state to join the United States of America. At the top of the seal is the sun, with thirteen rays protruding outwards. The thirteen rays represent the thirteen colonies that became the original thirteen states of the United States. Some early versions of the seal also had a canal boat on the river.

According to historical lore, the seal was based on the eastern view from Adena, the home of Thomas Worthington near Chillicothe. Worthington was one of Ohio's first two United States senators and he served as the sixth governor of the state. Today, Adena is a museum operated by the Ohio Historical Society. Most scholars now believe that Adena's view did not inspire the seal.