How to prevent users from connecting SharePoint Sites to Office 365 Groups?

Office 365 Group is a security (membership) group that is tied to various apps that we are subscribed to as part of our 365 subscription. It provide us distribution list, outlook calendar, site collection. The files tab in office 365 group points to document library on sharepoint site. We can associate team with the Office 365 group.

When we connect our Sharepoint site to a new Office 365 group, a number of things happen:

• A new Office 365 group is created, and that group is connected to our site collection
• A new modern home page is created on our site and set as the site’s home page
• The group’s Owners are now the site collection administrators
• The group’s Owners are added to our site’s Owners group
• The group’s Members are added to your site’s Members group

After our site is connected to an Office 365 group, it behaves like a modern group-connected team site, so granting people permission to the connected Office 365 group now also grants them access to the SharePoint site, a Microsoft Team can be created on top of the site, Planner can be integrated, and so on.

Remember how in the very first step we clicked on Gear Icon > Connect to new Office 365 Group? What if we do not want our SharePoint Site Admins to do this on their own (for governance reasons).  We can disable the ability to connect to Office 365 Groups from a SharePoint Admin Center. Here is how to do this:

Navigate to SharePoint Admin Center

Click on Settings

Scroll down to Connections from sites to Office 365 groups section and choose Prevent site collection administrators from connecting sites to new Office 365 groups option.

Click OK at the bottom. Give it a few minutes for a change to propagate through.