A banner is a flag or other piece of cloth bearing a symbol, logo, slogan or other message. Banner-making is an ancient craft.

The word derives from late Latin bandum, a cloth out of which a flag is made (Latin banderia, Italian bandiera). German developed the word to mean an official edict or proclamation and since such written orders often prohibited some form of human activity, bandum assumed the meaning of a ban, control, interdict or excommunication. Banns has the same origin meaning an official proclamation, and abandon means to change loyalty or disobey orders, semantically "to leave the cloth or flag".