Is Portal 1 on Xbox 360? Yes—Via The Orange Box

Yes. Portal launched on Xbox 360 in 2007 as part of The Orange Box (disc and digital). The compilation includes:

• Half-Life 2
• Half-Life 2: Episode One
• Half-Life 2: Episode Two
• Team Fortress 2
• Portal

The Orange Box is backward compatible on Xbox One and Xbox Series X|S. You can also buy Portal standalone digitally on the Xbox Store (often bundled with Portal 2 in the Portal Bundle).

Note: The Xbox 360 version runs at 720p/30fps with occasional slowdown in heavy particle scenes. The PC version (Steam) is superior: 60fps+, mods, workshop maps, free.