With the continuous growth of economy and population, electrification, industrialization, and urbanization, Association of Southeast Asian Nations (
ASEAN
) energy demand will be more than tripled during 2010–2035, which will create huge pressure on energy supply, energy security, and the environment. Energy efficiency, which offers a possible measure to mitigate the demand shock, is particularly important in
ASEAN
because of the dramatic energy demand growth and vast energy saving potential. Many
ASEAN
countries have implemented various measures to promote energy efficiencies, with Thailand, Singapore, and the Philippines being the leaders. The development of energy efficiencies in
ASEAN
members, in terms of sectoral goals, action plan, policy measures, activities, and achievements, however, is unbalanced, which offer opportunities for regional cooperation. Good practice in some
ASEAN
members in the areas of goals, policy instruments, standards, labeling, and financing offer lessons for the others. Regional cooperation has been present in the past few decades fueled by
ASEAN
dialog countries and is further boosted by the building of
ASEAN
Economic Community. The considerable economic benefits from the cooperation will further sustain the energy cooperation.