The concept of human security was first introduced formally in the 1994 UNDP Report and signaled a significant shift of focus from state security to the security of individual human beings and human communities. Unlike the abstract and theoretical debates within academia around that time about deepening and widening the definition of security, the human security approach was born from within the policy world and was policy-oriented. In the thirty years since its introduction, human security has undergone a series of reformulations, come under serious criticism, and inspired significant policy initiatives and numerous debates. Nevertheless, it remains the most formidable contender against traditional state-centered thinking around national and international security. In this chapter, we will look at the emergence and evolution of the human security approach, its core components, and its relationship with other important notions such as human development and responsibility to protect.