Which Pokémon game first used three-dimensional Pokémon models?

Pocket Monsters Stadium was the first Pokémon game to use three-dimensional Pokémon models.

Released in Japan for the Nintendo 64 in 1998, Pocket Monsters Stadium was developed and published by Nintendo. It focused on battles rather than a traditional journey through towns and routes, allowing Pokémon from the Game Boy games to appear as animated 3D models.

The title is often confused with Pokémon Stadium, the later international release. The Japanese Pocket Monsters Stadium supported only 40 Pokémon for battles, while the later Pokémon Stadium used all 151 species from Red, Blue, and Yellow. International naming also makes historical lists difficult to compare.

The game established the console-based 3D battle format that the Pokémon Stadium series continued. Pokémon Snap followed in 1999 and also featured real-time 3D Pokémon, but it was a photography game and came after Pocket Monsters Stadium. Mainline Pokémon games did not use fully 3D graphics until Pokémon X and Y on Nintendo 3DS.