Metal Gear Solid: Portable Ops (commonly abbreviated to MPO) is a stealth game directed by Masahiro Yamamoto, with series creator Hideo Kojima acting as a producer. Portable Ops was developed by Kojima Productions and published by Konami in 2006 for the PlayStation Portable. It is the third Metal Gear title for the PlayStation Portable and the first one to retain the series' action-based gameplay. It is also the first canonical outing of the series for a portable platform, being a direct sequel to Metal Gear Solid 3: Snake Eater.

Set in 1970 in South America, six years after the events of Snake Eater, the game follows the exploits of Big Boss after his former unit, FOX, goes renegade. The game also chronicles the eventual founding of FOXHOUND, as well as the inspiration of the military state Outer Heaven.