Due to their unique geographical, ecological, social, and economic characteristics, islands occupy a special place in international approaches and policies concerning biodiversity conservation and sustainable development. Resource limitations, geographical isolation, ecosystem fragility, high levels of endemism, and the interdependence between terrestrial and marine environments render these regions vulnerable to threats such as climate change, sea-level rise, invasive species, and habitat destruction. This study examines the evolution of the status of islands within the documents, programs, and initiatives of international organizations, analyzing the approaches adopted by the United Nations Convention on the Law of the Sea (UNCLOS), Agenda 21, the Convention on Biological Diversity (CBD), the International Union for Conservation of Nature (IUCN), and UNESCO’s Man and the Biosphere (MAB) Programme. The research employs a descriptive-analytical methodology based on the review of official international documents and reports. The international perspective has evolved from an initial focus on the legal definition and maritime status of islands toward recognizing the global importance of their biodiversity, integrated ecosystem management, climate change adaptation, and the linkage between environmental conservation and sustainable development. Furthermore, the emergence of dedicated programs and international cooperation networks reflects an increasing focus on the specific characteristics and needs of islands. Ultimately, the sustainable management of islands requires the adoption of an integrated, ecosystem-based approach that is rooted in the participation of local communities.