How Many Halo Games Were on the Original Xbox?

Two.

1. Halo: Combat Evolved – Launch title, November 15, 2001.
2. Halo 2 – November 9, 2004.

Notes

• Halo 3 (2007) launched on Xbox 360 only.
• Halo Wars (2009) – RTS, Xbox 360 only.
• Halo: Combat Evolved Anniversary (2011) – Remaster, Xbox 360.
• Halo: The Master Chief Collection (2014) – Includes both original Xbox games (remastered), on Xbox One/PC.

Original Xbox library: 2 mainline Halo FPS games.