Over the last few decades, the Association of Southeast Asian Nations (ASEAN) region has rapidly developed, seeing tens of millions of people become city dwellers. The region’s urban population is estimated to be almost 405 million out of a total population of almost 726 million, despite the rapid urbanization faced by ASEAN. It is reported that most ASEAN cities are polluted by air. Some ASEAN countries also reported an alarming number of deaths from lower respiratory infections; trachea, bronchus, and lung cancers; ischemic heart disease; stroke; and chronic obstructive pulmonary disease due to the highest levels of PM2.5, most exceeding WHO’s annual mean. Ambient air pollution sources come from transport, waste management, industry supply, agricultural practices, and household energy. However, air pollution in most countries in ASEAN comes from transportation. A high share of powered two- and three-wheelers adds to cities’ congestion and air pollution problems. A recent review of sustainable development describes progress toward making cities inclusive, safe, resilient, and sustainable in Southeast Asia as very slow and stagnant, contributing to the urgent need to accelerate efforts in this area. Thus, the aim of this study is to review the reality of the current situation in ASEAN and describe the countries’ practices of a sustainable approach. This aligns with SDG11 toward making cities safe and sustainable by focusing on achieving zero carbon emissions.