To list the user profiles of all SharePoint Online users in your tenant you can follow these steps
- Navigate to the User Profiles tab in the SharePoint Administration Center and click Manage User Profiles
- In the “Find profiles” text box type i:0#.f|membership
- Click the Find button to see the list of all user profiles
Note
- Currently there is no way to list external users (PALs)
- In case you wonder – the “f” in the search string means we are using forms based authentication

