Competency is an important concept in education and is at the core of future curriculum. The term “competency” is defined as an integrated concept of knowledge, ability and attitude. “Key” or “core competencies” can be broken down into critical competencies, necessary competencies and important competencies. Several international organizations, such as the United Nations Educational, Scientific and Cultural Organization (UNESCO), the European Union (EU), the Organization for Economic Co-operation and Development (OECD) emphasize the importance of key competencies in educational reform. In this paper, the author argues that the rationale and theoretical foundations of key competencies form different academic disciplines, such as philosophy, anthropology, psychology, economics and sociology, all of which contribute a set of relevant key competencies from their own theoretical backgrounds and disciplinary perspectives.