Create sub domain for SharePoint online

[mgmjtech2120]

Is it possible to create a sub domain to host SharePoint Online?

Example:

root domain. contoso.com - Sharepoint online, Onedrive, exchange, Microsoft Entra ID, etc.

sub domain.  test.contoso.com - SharePoint Online.

Users can use the same Microsoft Entra IDs to login:

https://contoso.com/sites/sales

https://test.contoso.com/sites/marketing

[#2]

Hi,

No, SharePoint Online does not support subdomains

[#3]

@mgmjtech2120 Not for SharePoint, but check below Microsoft official documentations for the possibilities to add domains in M365:

1. Add a domain to Microsoft 365 
2. Can I add custom subdomains or multiple domains to Microsoft 365? 

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