If you previously bought a backward compatible game on Xbox 360 or have a game disc, you can play it on your Xbox One or Xbox Series X|S console. Only digital purchases will work on Xbox One S All Digital Edition and Xbox Series S. Additionally, some games or downloadable content may not be available in all regions.

Yes, as of my last update in September 2024, "Call of Duty: Black Ops 1" is backwards compatible with the Xbox One.