About removal of enterprise members
If you enterprise does not use Enterprise Managed Users, you can remove an enterprise member from GitHub. When you remove a member from your enterprise, the member is removed from all organizations owned by your enterprise.
If the enterprise member you're removing is the last owner of an organization owned by your enterprise, you will become an owner of that organization.
If your enterprise or any of the organizations owned by your enterprise uses an identity provider (IdP) to manage organization membership, the member may be added back to the organization by the IdP. Make sure to also make any necessary changes in your IdP.
If your enterprise does use Enterprise Managed Users, you must remove the enterprise members through your identity provider (IdP) and the SCIM integration instead. For more information, see "About Enterprise Managed Users."
Removing a member from your enterprise
Note: If an enterprise member uses only GitHub Enterprise Server, and not GitHub Enterprise Cloud, you cannot remove the enterprise member this way.
In the top-right corner of GitHub.com, click your profile photo, then click Your enterprises.
In the list of enterprises, click the enterprise you want to view.
In the enterprise account sidebar, click People.
To the right of the person you want to remove, select the dropdown menu and click Remove from enterprise.