All-Star Baseball 99 is a video game developed by Iguana Entertainment and Realtime Associates Seattle Division and published by Acclaim Entertainment for the Game Boy and the Nintendo 64 in 1998. The game's cover features Colorado Rockies outfielder Larry Walker.

All-Star Baseball 99 was the first game to use Acclaim's Quagmire engine. The game also marked the debut of play-by-play commentary for the series. This is done by two New York Yankees broadcasters: John Sterling and Michael Kay.

The game contains exhibition, playoff, home run derby, and season modes. A "create-a-player" feature for customized ball players is included.