IG may refer to any of the following:
IG is an abbreviation often used for Instagram.
Short for in-game, IG describes something that happens or exists in a game rather than in real-life. For example, an in-game currency is money that only exists in a game and not in real-life.
IG is an abbreviation for “I guess” sometimes used in chat.
IG is sometimes used as an abbreviation for ignore.
IG is sometimes used to shorten “ignorant.”
Computer acronyms, Game terms