What was the name of Pokémon's first handheld game system?

Pokémon's first games were released for the Game Boy.

Pocket Monsters Red and Green launched in Japan for Nintendo's Game Boy on February 27, 1996. The system's link cable made trading and battling between players possible, a feature that became one of Pokémon's defining innovations. Different Pokémon versions encouraged players to connect and exchange creatures unavailable in their own copy.

The international releases Pokémon Red and Blue also appeared on the original Game Boy. They were later playable on the Game Boy Color, but the first-generation games were designed for the original monochrome-compatible Game Boy platform.

This distinction matters because Pokémon Yellow was released for the Game Boy as well, while later generations moved to newer hardware. Pokémon Gold and Silver supported both Game Boy and Game Boy Color, and Pokémon Ruby and Sapphire were developed for the Game Boy Advance.