https://www.theregister.co.uk/2019/11/28/now_you_can_use_an_office_365_account_to_sign_in_to_aws/

Just ahead of its big Las Vegas re:Invent knees-up, Amazon Web Services (AWS) has extended its Single Sign-on service to support Azure Active Directory – as used by Microsoft's Office 365.

"Today we announced the next evolution of AWS Single Sign-On, enabling enterprises that use Azure AD to leverage their existing identity store with AWS Single Sign-On," said the cloud giant. "Additionally, automatic synchronization of user identities, and groups, from Azure AD is also supported."