A green card is a card that signifies fair play or is used to discipline players for unsportsmanlike behavior. It was first used in the CONIFA World Football Cup in June 2018, which is a tournament for non-FIFA affiliated international teams. The green card is intended to promote ethical values in the sport and encourage players to play fairly.

When a player receives a green card, they must leave the field of play immediately, but can be replaced if their team has not used all of their substitutes. A player receiving a green card is not excluded from their teams next match. The green card is awarded to teams that fulfill certain criteria, such as lining up and shaking hands with the opposing team and match officials before each game. Each team can earn a maximum of one green card per game, and teams that fail to earn a green card in even one of their games will not be eligible to go forward to Future Football Cup events at regional and national levels.

The green card is not widely used in professional football, and there are no plans to have it at the upcoming World Cup in Russia or professional football in England. However, it has been used in Italys Serie B after an "act of virtue" or fair play in the game, and at grassroots level in Ireland. The green card is seen as a way to sanction and limit unsportsmanlike behavior, and to encourage players to play fairly.