A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Dear DevOps Netstager,
Good day to you!
I hope you are doing well. Thanks for reaching out to our Microsoft Community Forum. We will be happy to help you.
According to your description, you want to share your SharePoint site only within your organization and prevent external user access. I’m happy to share the steps you can try.
You can configure this setting at the tenant level through the SharePoint Admin Center. Navigate to the admin center, go to Policies, select Sharing, and set the sharing option to "Only people in your organization." Scroll down the option to Least permissive. This ensures that external users cannot access the site. Here is the screenshot for your reference:
If you want to restrict access to a specific SharePoint site, open the site, click on the Settings icon in the top-right corner, select Site Permissions, then go to Advanced Permission Settings. From there, remove any external users or groups from the permission list to ensure only internal users have access. Here is the screenshot for your reference:
To further enhance security, go to Policies in the SharePoint Admin Center, select Access Control, and enable OneDrive Access Restrictions with Site-Level Access Restrictions. Here is the screenshot for your reference:
Lastly, verify that only internal users are included in the Owners, Members, and Visitors groups of your site to maintain controlled access.
Here is the Microsoft Official article for your reference: Sharing & permissions in the SharePoint modern experience - SharePoint in Microsoft 365 | Microsoft Learn.
If you have any questions, please feel free let us know for further assistance.
Thank you for your understanding. Your cooperation and contributions are greatly appreciated.
Kind Regards,
Nahid Sultan