Small Island Developing States are under significant threat from global change and unsustainable local practices. These issues are generally exacerbated by an inherent vulnerability to social, economic and ecological changes consequential to their unique island characteristics (e.g. limited resources), which is often described as “islandness”. These unique island characteristics or “islandness” have shaped, and continue to shape, their socio-ecological systems which, from a real-world geographic perspective, the island and its communities form an integrated socio-ecological landscape. It can be argued that “islandness” contributes immensely to understanding the socio-ecological systems of an island, and in considering “islandness” as a fundamental element that significantly influences socio-ecological systems on islands, socio-ecological systems then materialise as socio-ecological islandscapes. This study ultimately sets out to initiate the development of the socio-ecological islandscape concept through (1) providing the preliminary framework, and (2) gaining insights into what impact each of the unique characteristics of “islandness” has on a system, both as individual components and as a collective, through the use of Bayesian Belief Networks. The results of the study provide evidence of the influence that “islandness” has on both the social and ecological components of a socio-ecological system. Differences in degree of influence between the unique island characteristics (e.g. size vs. isolation) also showed how some characteristics have greater impacts. The socio-ecological islandscape framework proposed in this study propagates a research agenda focused on the SES-landscape-SIDS-islandness nexus, due to its apparent effect on the economic disadvantages and ecological fragility faced by SIDS that threatens their sustainability.