When you first create an Office 365 group, you can choose to make the group public or private. Previously in Office 365, you couldn’t change the privacy setting after you created the group. Now, you can change the privacy settings on an Office 365 group, in Outlook on the web, after you’ve created it. For example, you created a group for the human resources team at your company and made it a public group, but now, you want to make it a private group. You can quickly and easily change the privacy settings in a few steps.
Make a group private or public in Outlook on the web
2. In the upper-left corner of the page, choose App launcher > People.
3. Navigate to the Office 365 group that you want to change the privacy settings on.
4. From the group page, click or tap Edit group.
5. Under Privacy, choose Public or Private to match the setting you want.
6. Click Save to make your selection, and close the page. It may take a few minutes for the changes to take effect.