Pokémon Pokopia's initial roster included 300 Pokémon.
The selection covers species from Generations I through IX and forms the population that players encounter while rebuilding the world. The roster is integrated into the game's habitat system: Pokémon appear in places suited to their preferences, so town planning and environmental design influence which creatures become residents.
This number describes the game's included Pokémon roster, not the number of Pokémon species ever created. The broader franchise contains many more species, and Pokopia deliberately uses a curated selection suited to its social simulation format.
The roster also should not be confused with the number of players supported in a town. Pokémon count and multiplayer capacity are separate facts. Pokopia's focus is on creating a lively habitat filled with Pokémon, while its multiplayer feature concerns how many people can visit or build together. The 300 figure applies to Pokémon available in the game itself.