Was Halo 2 Ever Released on PlayStation 2?

No. Halo 2 was never released on the PlayStation 2. It was developed exclusively for the original Xbox by Bungie and published by Microsoft Game Studios. The game launched on November 9, 2004, as an Xbox exclusive and was later ported to Windows Vista in 2007 (as Halo 2 for Windows Vista), but it never appeared on any Sony platform.

The Halo franchise has historically been a cornerstone of Xbox exclusivity, with mainline entries remaining on Xbox and PC platforms only.