The Fox Engine is a cross-platform game engine built by Kojima Productions for use in future titles developed by the team. It is believed that this engine is designed for the next generation of video games. The engine was revealed by Konami on June 3, 2011. The engine's development began after the completion of Metal Gear Solid 4: Guns of the Patriots with the goal of making the "best engine in the world."

The engine will make it possible for Kojima Productions to develop multiplatform games with a significantly shortened development time and has been described as the first step for the developer to move away from development for a single platform. The engine is named after FOX, a fictional military unit from the Metal Gear series, wherein is also a reflection of Kojima Productions itself, which based its company logo on FOX's fox emblem.