The Flag-Smasher is the name used by several anti-nationalist supervillains appearing in American comic books published by Marvel Comics. The character first appeared in Captain America #312 in December of 1985. The first and original incarnation is Karl Morgenthau, a supervillainous terrorist who becomes rivalled with Captain America and is also the leader of U.L.T.I.M.A.T.U.M., a terrorist organization that wants to unite mankind and separate them from their symbols; and the second was Guy Thierrault. Other versions of the character include LMD, Grant Rogers, and Captain Anarchy. They are also enemies of the Punisher, Moon Knight, Ghost Rider, the Runaways, the Liberteens and Deadpool.
A group called the Flag Smashers appeared in the Marvel Cinematic Universe / Disney+ series The Falcon and the Winter Soldier (2021), led by a female version of the Karl Morgenthau incarnation renamed Karli Morgenthau (portrayed by Erin Kellyman).