The Oceania region, which unites 19 states and territories, has its own environmental problems that require the adoption of appropriate documents to solve them. Using a legal — historical approach, this article revisits the 1976 Apia Convention — the first multilateral environmental treaty concluded by the island states and territories of Oceania — and evaluates its enduring normative and institutional imprint on regional governance. It traces how the Convention’s pioneering obligations to establish protected areas, safeguard endemic and migratory species, and control alien introductions catalysed the creation of the South Pacific Regional Environment Programme (SPREP) that was transformed into an international intergovernmental organization in 1993. It was SPREP that became the basis for instruments such as the 1986 Noumea and 1995 Waigani Conventions. The analysis reveals that, despite entering into force only in 1990 and being formally “suspended” in 2006, the Apia Convention continues to serve as a doctrinal touchstone: national courts and inter-state negotiations still cite its due diligence standard when expanding marine reserves or debating high-seas biodiversity. At the same time, the study identifies structural weaknesses of the convention — a low number of ratifications, voluntary compliance and the absence of enforcement machinery — that limit the Convention’s practical reach, particularly regarding the 21st-century threats such as plastic pollution, deep-sea mining and climate-induced migration. Building on recent political momentum, the authors propose a three-pillar reform package: optional protocols on plastics and seabed extraction; dynamic incorporation of the Paris Agreement and the Biodiversity Beyond National Jurisdiction (BBNJ) Convention obligations; and a strengthened reporting and a majority vote amendment procedure.