Metal Gear Online is a forthcoming online spinoff of the Metal Gear series produced by Konami. The game was officially unveiled in Kojima Productions' 20th Anniversary Part of the Metal Gear series. While the previously released Metal Gear Solid 3: Subsistence and Metal Gear Solid: Portable Ops featured optional online game modes that were both dubbed Metal Gear Online, this incarnation of the online game was initially announced as a separate stand-alone product based on the Metal Gear Solid 4: Guns of the Patriots gameplay and setting, but has since been announced as part of Metal Gear Solid 4. An online beta test was released exclusively in Japan, which occurred from August 20, 2007 through September 3, 2007. The beta was only open to 3,000 players. In addition to announcing a ship date and hardware bundle for Metal Gear Solid 4: Guns of the Patriots, SCEA revealed that a beta for the game's online component will happen before the June release. Metal Gear Solid 4 will come with a "starter pack" that will be expanded upon with extra content.

The multiplayer beta test for Metal Gear Online will begin in late April and will be open to those who pre-order the game in North America, a beta is also planned for Europe.