The Flag of the Czech Republic is the same as the flag of the former Czechoslovakia. Upon the dissolution of Czechoslovakia the Czech Republic kept the Czechoslovak flag while the Slovak Republic adopted its own flag.

The author of the flag is somewhat disputed but most vexillologists agree on Jaroslav Kursa (1875–1950), an archivist of the Department of Home Affairs, as the original author of the present flag appearance. The flag contains red and white colors derived from the ancient Coat of arms of Bohemia; because the flag was almost identical with the Polish flag and had the same colors as the Austrian flag, a blue wedge was added in 1920. (The version without the wedge is identical to the flag of Bohemia.) The blazon is per pall fesswise Argent, Azure, and Gules.