Was Tony Hawk's Project 8 Released on GameCube?

No. Tony Hawk's Project 8 (2006) was not released on Nintendo GameCube.

Platforms It Released On

• PlayStation 2
• Xbox
• Xbox 360
• PlayStation 3 (as a launch title, Nov 2006)
• PSP (distinct version by Page 44 Studios)

GameCube Tony Hawk History

The GameCube received the previous two mainline entries:

• Tony Hawk's Underground (2003)
• Tony Hawk's Underground 2 (2004)

By the time Project 8 launched, Nintendo had moved focus to the Wii (released Nov 2006). The Wii received Tony Hawk's Downhill Jam (2006) instead—a different, arcadey downhill racer.

If you want the "classic" THPS feel on Nintendo hardware, THUG 2 on GameCube (or Wii via backward compatibility) is the last mainline entry.