Which main-series Pokémon game first featured a playable female Pokémon Trainer?

Pokémon Crystal was the first main-series Pokémon game to feature a playable female Pokémon Trainer.

Released for the Game Boy Color in Japan in 2000, Crystal is an enhanced version of Pokémon Gold and Silver. Players can choose between a male protagonist and Kris, the series’ first selectable female player character.

Earlier main-series games allowed players to name and control a male protagonist, but they did not offer a gender choice. Crystal therefore changed the player’s role without abandoning the Johto setting, the Gold and Silver storyline, or the second-generation Pokémon roster.

Kris should not be confused with later female protagonists such as May in Pokémon Ruby and Sapphire, Dawn in Pokémon Diamond and Pearl, or Lyra in the HeartGold and SoulSilver remakes. Those characters belong to later games, while Crystal introduced the option itself.