Pokémon: Battle Frontier

Pokémon: Battle Frontier is the ninth season of the Pokémon anime series and the fourth and final season of Pokémon the Series: Ruby and Sapphire, known in Japan as Pocket Monsters: Advanced Generation (ポケットモンスター アドバンスジェネレーション, Poketto Monsutā Adobansu Jenerēshon). It originally aired in Japan from October 6, 2005, to September 14, 2006, on TV Tokyo, and in the United States from September 9, 2006, to March 3, 2007, on Cartoon Network.

The season follows Ash Ketchum and his partner Pikachu as they compete in the Battle Frontier for Frontier Symbols in the Kanto region. They are joined by Brock, as well as May, who participates in Pokémon Contests to earn Ribbons for the Grand Festival, and her younger brother Max.

The episodes were directed by Masamitsu Hidaka and Norihiko Sudo, and were produced by the animation studio OLM.

This is the first season of Pokémon to be localized into English by Pokémon USA after 4Kids Entertainment's contract was not renewed.