Concepts and technologies are disclosed herein for tag-based security policy creation in a distributed computing environment. A security management module can receive an inventory event that relates to instantiation of a service. The security management module can identify the service that was instantiated and obtain a tag set that relates to the service. The tag set can include security tags that include a string that identifies a communications link associated with the entities included in the service that was instantiated. The security management module can identify policy rules associated with the security tags. The policy rules can define security for the service that was instantiated. The security management module can compute a security policy for the service and can provide the security policy to the computing environment for implementation.