Guitar Hero on Wii: Internet Required? No

No, you do not need an internet connection to play Guitar Hero on Wii.

What Works Offline

• Full Career / Quickplay: All on-disc songs playable solo or local co-op.
• Local Multiplayer: Versus, Co-op, Band modes with 2+ controllers.
• Previously Downloaded DLC: Songs purchased/downloaded before going offline remain playable.

What Requires Internet

• Purchasing New DLC: Wii Shop Channel (closed 2019) – no new purchases possible.
• Online Leaderboards / Multiplayer: Defunct for most GH Wii titles.
• GH: World Tour / 5 / Warriors of Rock – Music Studio Sharing: Requires connection (servers likely down).

Since the Wii Shop Channel is closed, all DLC is now permanently unavailable for purchase. Only on-disc content and previously downloaded songs work.