Leave no one behind (LNOB) is the central, transformative promise of the 2030 Agenda for Sustainable Development and its Sustainable Development Goals (SDGs). Between 2012 and 2022, Thailand has made significant progress in enhancing equality of opportunity. Out of 20 SDG indicators analyzed, 12 are either universally accessed or nearly universal. The challenge ahead is to close the gaps for the furthest behind groups in remaining indicators such as completion of secondary and higher education as well as access to clean fuels.