In Vs. Golduck, Misty reveals she owns a Starmie. It is kidnapped by Cobalt, along with Misty's other Pokémon. They are rescued by the end.
In Vs. Gyarados, Starmie is chosen to battle Ian. It battles his Squirtle first, and defeats it with ease. Ian chooses Bulbasaur next, and despite a life disadvantage, wins, utilizing a Water Pulse using the whole water field. It then battles Gastly, and is defeated easily.
In Vs. Dewgong, Misty uses Starmie to battle Ian again. It first battles Ian's Croconaw, defeating it with its new Thunderbolt attack. It then battles Ian's Omastar, the battle becoming much harder. However, Starmie perseveres, and wins. This allows Misty to win the Whirl Cup.
In Gym Leader Tournament 2, Misty uses Starmie to battle Morty's Misdreavus. Morty wins with ease.
In Vs. Snagem, Starmie is chosen to fight Team Snagem. When Shadow Lugia attacks, it is weakened and snagged/stolen by Team Snagem. It is transformed into a Shadow Pokémon after that.
In Vs. Shadow Starmie, Venus uses Shadow Starmie to battle Crystal's Mismagius and Roserade. Starmie manages to defeat Mismagius, and is weakened by a combo from Roserade and Buizel. This allows Crystal to snag it.
In Vs. Shadow Delcatty, Crystal chooses Starmie and Roserade to battle Lovrina's Gorebyss, Beautifly and Shadow Altaria. Starmie is defeated by Beautifly, but its Shadow Sky allows for Roserade to use a Shadow powered Weather Ball.
In Vs. Shadow Electivire, Crystal chose Starmie to help light their way through the black out with its Illuminate ability.