Pokémon Stadium 1 was released in 1999 (Japan) and 2000 (international) for the Nintendo 64. Although this was the second Stadium game to be released in Japan, it was the first to be released in English-speaking regions, so it is typically called 'Stadium' or 'Stadium 1' by English-speaking fans.
In this game, the player can use Pokémon from their copies of the Game Boy games Red, Green, Blue, or Yellow to battle other human players or computer-controlled opponents. There are also rental Pokémon that the player can use, but their stats and movesets are usually inferior to those that could be created from a copy of one of the Game Boy games. It is, however, possible to complete the game's challenges using only rental Pokémon, although it does rely on luck.
Beating a challenge registers the Pokémon used in the team to the Hall of Fame. Registering all 151 Pokémon to the Hall of Fame awards the player a Psyduck that knows Amnesia that can be traded to a copy of Red, Green, Blue, or Yellow.
In addition to battling, the player can also interact with a connected copy of a Game Boy Pokémon game in a variety of ways. The player can:
The game also features a handful of multiplayer minigames that can be played with up to four players.
All 151 Pokémon available in Red, Green, Blue, and Yellow can be used in this game, but not every species can be used in every cup. Details are given on the individual cups' pages.
In April 2023, Pokémon Stadium 1 was rereleased for the Nintendo Switch as part of the Nintendo Classics program on Nintendo Switch Online. Unlike the original releases, this version is not capable of communicating with any other Pokémon game. This means that all battle challenges must be completed with only rental Pokémon, and the gift Pokémon obtained as rewards for clearing certain challenges cannot be used for anything.