The launch of the Association of Southeast Asian Nations (ASEAN) Community in December 2015 is expected to accelerate structural transformation in Southeast Asia. It is also an initiative that shifts the landscape of higher education in Southeast Asia, which needs to meet the challenges posed by the process of regionalization of higher education. Based on the review of theoretical and conceptual works on regionalization in higher education, a broader scope of regional cooperation in higher education in Southeast Asia is suggested. Such broader scope is enable to survey the main actors (stakeholders) engaged in regional cooperation in higher education in Southeast Asia at multiple levels of cooperation: universities/higher education institutions (HEIs); government/intergovernmental cooperation; and intra-/interregional cooperation. Furthermore, two priority areas for harmonization in higher education, namely, quality assurance (QA) and credit transfer, are highlighted as particular forms of regional cooperation. Both internal and external QA systems are explained. In particular, the Academic Credit Transfer Framework for Asia (ACTFA) is introduced, which would serve as a main framework for credit transfer for Southeast Asia, by embracing credit transfer system/scheme which exist in Southeast Asia. In lieu of conclusion, main actors (stakeholders) including their mechanisms to engage in regional cooperation in higher education are summarized according to functions such as capacity building, credit transfer, grading, student mobility, mutual recognition, qualification framework, and quality assurance. Future directions in regional cooperation are suggested to pave the way towards the creation of a “common space” in higher education in Southeast Asia, or eventually the Southeast Asian Higher Education Area (SEAHEA), by developing and adapting common rules, standards, guidelines, and frameworks to be applicable to Southeast Asia.