Ports are increasingly ‘greening’ operations to protect their ‘license to operate’ by integrating social-environmental considerations into their management and reporting on their sustainability performance. In this research, we develop a novel method for port sustainability performance (PSP) assessment that combines science-based knowledge with place-based contextualisation. Specifically, we address a recognised challenge of combining global (‘top-down’) techno-scientifically oriented indicators with place-based locally relatable (‘bottom-up’) contexts in sustainability performance, in addition to addressing limitations encountered in empirical verification. First, a critical evaluation of the international literature on port sustainability assessments is undertaken to distil commonalities in global performance indicators, and to identify typical frames used in the design of sustainability performance indices. We apply this learning, together with place-based experiential knowledge, to develop a science-based framework for a Port Sustainability Performance (PSP) Index that is explicitly aligned with the Sustainability Development Goals (SDGs). We then apply a co-design process to demonstrate local customisation of the index to derive place-based quantifiable measures and targets. Further, for easy-to-use empirical verification, a simple spreadsheet is applied to develop a flexible weighted scoring matrix. The matrix uses place-based rating systems for selected measures and associated targets, and aggregates allocated scores into informative outputs. Finally, the concept of Circles of Sustainability is adapted for ports to visually display sustainability performance, in alignment with related SDGs. This research contributes to bridging the science-practice divide in reporting on port sustainability performance.@en