The Association of Southeast Asian Nations (ASEAN) was created in 1967 with five member countries (Indonesia, Malaysia, Singapore, Philippines, Thailand) and has expanded several times since then, most recently when Cambodia became a member in 1999. Two countries, Papua New Guinea and Timor-Leste, have observer status, and a number of others have expressed interest in joining.

This market is about which countries will join the organisation as full members (not just observers) on or before 31 December 2029. The official date of accession will be used. If ASEAN is renamed, answers can still resolve to YES.