Vratislav I, Duke of Bohemia (915- February 13, 921), was the younger brother of Spytihnev I.

Vratislav had two sons, Václav and Boleslav. The Chronicle of Fulda reports that in 900 the Bavarians attacked Moravia in alliance with the Bohemians. Vratislav died (possibly in 919, although 921 is more often conjectured) in battle against the Magyars.