One Piece: Grand Adventure is a 3D arena-style fighting game developed by Ganbarion and published by Bandai Namco.

It is the sequel to One Piece: Grand Battle and was released exclusively for PlayStation 2 and Nintendo GameCube in 2006 (North America and Europe only).

Grand Adventure combines arena-style combat with RPG-lite progression, allowing players to build a custom pirate crew, level up characters, and sail through different islands as part of an original adventure mode.