AWS Directory Service
Administration Guide (Version 1.0)

Use Case 5: Extend your on-premises AD to the AWS Cloud

If you already have an AD infrastructure and want to use it when migrating AD-aware workloads to the AWS Cloud, AWS Microsoft AD can help. You can use AD trusts to connect AWS Microsoft AD to your existing AD. This means your users can access AD-aware and AWS applications with their on-premises AD credentials, without needing you to synchronize users, groups, or passwords.

For example, your users can sign in to the AWS Management Console and Amazon WorkSpaces by using their existing AD user names and passwords. Also, when you use AD-aware applications such as SharePoint with AWS Microsoft AD, your logged-in Windows users can access these applications without needing to enter credentials again.