Social enterprise (SE) is a notion that has been little discussed in France, Spain and Portugal by comparison with other national contexts. This chapter explains that this situation can be accounted for by a strong social-economy tradition in these three countries—which also share the fact that the social economy as a sector has recently been institutionalised through the adoption of a specific law (Spain, Portugal and France). It compares the emergence and development of social enterprise in France, Spain and Portugal, which is linked, to a large extent, to the social-economy tradition. The chapter analyses social enterprises as organisations that are located between three poles that coexist in France, Spain and Portugal: the social economy, the solidarity economy and social entrepreneurship.