Ratchet & Clank: Up Your Arsenal is a 2004 3D platform video game developed by Insomniac Games and published by Sony Computer Entertainment for the PlayStation 2.

The gameplay is similar to previous games in the series but introduces new features such as a new control system and more levels in the upgrade system for weapons. It follows Ratchet and Clank's adventure through a fictional universe to defeat a robotic villain, Dr. Nefarious, who intends to destroy all organic life. Characters such as Dr. Nefarious and Sasha, a Cazar starship captain who helps Ratchet throughout the game, are introduced, and a number of characters return from the original Ratchet & Clank.