This chapter describes the concept of social enterprise and explains the term ‘social entrepreneurship’. The term ‘social enterprise’ refers to a business activity intended to generate profit to finance a social, educational, cultural, religious, or charitable cause. A social enterprise is a for-profit business whose primary purpose is to reinvest its profits in not-for profit activities. There can be various types of social enterprises such as small-business entities, co-operative, social firm, credit union, trading arm to charity, and public sector spin-outs. The chapter explores the steps needed to develop a social enterprise and describes the key components of a business plan. The development of a social enterprise requires an investment, which implies some costs. The costs will be fixed and variable. The chapter emphasizes social entrepreneurship as a mission-driven enterprise and a strategy for financial sustainability in nonprofit organizations.