This chapter explores the framework and main principles of positive psychology (PosPsy) and its application within second language (L2) education. We begin by addressing the fundamental question: What is positive psychology? By outlining its core components, we aim to establish a comprehensive understanding of this field. We then discuss the connection between PosPsy and L2 education, highlighting the key frameworks and models of positive psychology. Furthermore, we examine why the integration of PosPsy is crucial for L2 education, based on the current literature. The chapter also provides an overview of the current state of research in this area, emphasizing the progress made and identifying key areas for future exploration. By the end of this chapter, readers will gain practical insight into the merger of positive psychology with L2 education and understand its transformative potential for language learners.