In accordance with an embodiment, described herein is a system and method for providing security in a multitenant application server environment. In accordance with an embodiment, per-partition security configuration includes: per-partition security realm (including configuration for authentication, authorization, credential mapping, auditing, password validation, certificate validation, and user lockout); SSL configuration, including keys, certificates, and other configuration attributes; and access control for partition and global resources. An administrator can designate one or more partition users as partition administrators, via grant of roles.