The Orange Box is a video game compilation containing five games developed by Valve. Two of the games included, Half-Life 2 and its first stand-alone expansion, Episode One, had previously been released as separate products. Three new games were also included in the compilation: the second stand-alone expansion, Half-Life 2: Episode Two, the puzzle game Portal, and Team Fortress 2, the multiplayer game sequel to Team Fortress Classic. Valve also released a soundtrack containing music from the games within the compilation. A separate product entitled The Black Box was planned, which would have included only the new games, but was later canceled.

The Orange Box was first released for Microsoft Windows and the Xbox 360 in October 2007. The Orange Box received critical acclaim, with Portal being recognized as a surprise favorite of the package.