Which US state's official flag is in the shape of a pennant?

The Ohio Burgee is the official flag of the U.S. state of Ohio. Ohio's swallowtail flag is the only non-rectangular U.S. state flag. Its red, white, and blue elements symbolize the state's natural features and order of admission into the Union. A prominent disc in the flag's triangular canton is suggestive of the state's name.

The flag was designed in 1901 by John Eisenmann for the Pan-American Exposition and adopted in 1902. Before that, for nearly a century after statehood, Ohio did not have a legally authorized state flag. One unsuccessful proposal called for a design based on the state seal.

Ohio has adopted an official salute to the flag and a 17-step procedure for folding it. The Ohio flag has influenced a number of logos and municipal flags within the state. A scarlet-colored gubernatorial flag is based on the state seal.