Does Minecraft on Xbox Require an Internet Connection?

No. Minecraft on Xbox (Xbox One, Series X|S, Xbox 360 Edition) supports full offline single-player.

• Single-Player/Creative/Survival: Play entirely offline; worlds save locally to the console.
• Multiplayer (Realms, Servers, Split-Screen LAN): Requires Xbox Live Gold/Game Pass Core (on Xbox One/Series) and internet.
• Split-Screen Local Co-op: Works offline on the same console (no Gold needed).

Initial download and updates need internet, but after that, solo play is fully offline.