Following the establishment of the Association of Southeast Asian Nations (ASEAN) on 8 August 1967 in Bangkok, Thailand, Parliamentarians across the region increasingly recognised the importance of ensuring ASEAN is grounded in the lives and aspirations of its peoples. This growing awareness underscored the need for a parliamentary dimension to complement intergovernmental cooperation.

Early parliamentary engagements provided the initial impetus for this idea. In August 1973, a Malaysian parliamentary delegation paid a visit to Indonesia, followed by a visit by a Singapore parliamentary delegation later that year in November. These exchanges helped generate momentum towards the establishment of structured parliamentary cooperation among the National Parliaments of ASEAN Member States.

Building on these developments, the House of Representatives of Indonesia took a proactive role in advancing the initiative by sending parliamentary missions in May 1974 to Thailand and the Philippines, and subsequently to Malaysia and Singapore in September, with the objective of seeking formal support for the creation of an ASEAN Inter-Parliamentary Forum. These efforts were met with positive responses from all the parliaments consulted, laying a strong foundation for the institutionalisation of regional parliamentary cooperation.

Following these consultations, the National Parliaments of ASEAN Member States agreed to convene the First ASEAN Parliamentary Meeting in Jakarta from 8 to 11 January 1975, to further deliberate on the proposal to establish a formal organisation comprising the parliaments of Indonesia, Malaysia, the Philippines, Singapore, and Thailand. The proposed organisation was envisaged as a meaningful parliamentary platform complement to ASEAN, contributing constructively to the region’s long-term goals and aspirations. It also sought to enhance the participation of the peoples of ASEAN in the pursuit of shared objectives, including economic, social, and cultural development, the safeguarding of regional political and economic stability, and the peaceful resolution of intra-regional differences.

At the Third ASEAN Parliamentary Meeting, held in Manila, the Philippines, delegates agreed to formally establish the ASEAN Inter-Parliamentary Organization (AIPO) through the signing of the AIPO Statutes on 2 September 1977. This milestone marked the birth of a regional parliamentary organisation in Southeast Asia. As ASEAN continued to expand, AIPO grew in parallel, reflecting the expansion of its membership alongside ASEAN’s enlargement.

Recognising the need for a more effective and closely integrated parliamentary institution, AIPO Member Parliaments agreed to transform AIPO into the ASEAN Inter-Parliamentary Assembly (AIPA). This transformation was formalised through the signing of the AIPA Statutes on 17 April 2007 in Kuala Lumpur, Malaysia. In the same year, ASEAN adopted the ASEAN Charter in November 2007, which formally recognised AIPA as an associated entity of ASEAN, as reflected in Annex 2 of the Charter, thereby further strengthening the Assembly’s role as the sole parliamentary organisation associated with ASEAN.

By 2011, following the accession of the Union Assembly of Myanmar to AIPA, the parliaments of all ten ASEAN Member States had become full-fledged members of the Assembly. Alongside its internal growth, AIPA also expanded its external engagement through the admission of Observer Parliaments. To date, AIPA counts twenty-six Observer Parliaments, reflecting the broader scope of its inter-parliamentary engagement beyond the ASEAN region.