Global and regional changes to the marine environment associated with climate change may have significant consequences for coral reef ecosystems, coastal communities, and maritime heritage resources relevant to the Fagatele Bay National Marine Sanctuary (FBNMS). Regional physical changes to the marine environment include climate variability, sea level rise, ocean circulation patterns, and ocean acidification. These changes combined with anthropogenic stressors may produce cumulative impacts on biodiversity and ecosystem health including changes in physiology, phenology, and population connectivity, and species range shift. This paper identifies and synthesizes potential climate change impacts in American Samoa and the region over the next fifty years. This information will help inform priority management actions for the Sanctuary to take to respond to the impacts of climate change on natural systems and human activities within American Samoa.