WSO2 Identity Server is the first Identity Server Bus in the industry which is capable of managing multiple user identities among applications, APIs, cloud, mobile, etc. One of the main components of the WSO2 Identity Server is user stores. Currently WSO2 Identity Server supports user stores related to LDAP, Microsoft Active Directory and Relational Databases such as MySQL, SQL Server, DB2 etc. With the fast growth of enterprise adoption of NoSQL databases in industry, WSO2 Identity Server needs to be expanded to support NoSQL Databases. In this project I will be implementing a user store support for WSO2 Identity Server based on MongoDB which is one of the most popular NoSQL database in industry today.