Settings → System → Groups → Delete

Hello Buzz … There is no such choice in Sonos neither on OS X nor iOS.  Can you be more specific.  

What iOS version is your device running on?

System requirements (S2 and S1)

• Android 7.0 or later
• iOS 11 or later
• iPadOS 13 or later
• macOS 10.11 or later
• Windows 7 or later

Group and ungroup rooms

Thanks … Got it.  

Hoolala !  So unintuitive and not obvious.  Could be so much easier if deleting a group was at the same place that you create them, and also if it was available on OS X as well.