The flags of the U.S. states exhibit a wide variety of regional influences and local histories, as well as widely different styles and design principles. Modern state flags date from the 1890s when states wanted to have distinctive symbols at the 1893 World's Columbian Exposition in Chicago. Most state flags were designed and adopted between 1893 and World War I.

According to a 2001 survey by the North American Vexillological Association, New Mexico has the best-designed flag of any U.S. state, U.S. territory, or Canadian province, while Georgia's 2001–2003 state flag was rated the worst design.