Risk screening tools are being increasingly used to identify the potential invasiveness and associated risks of non-native species. In this study, the Aquatic Species Invasiveness Screening Kit was used to evaluate the invasiveness risks of extant and horizon non-native marine fish species for the coastal waters of South Korea. In total, 57 marine fish species were screened and the threshold scores for the Basic Risk Assessment (BRA) and the BRA + Climate Change Assessment (BRA+CCA) (5.5 and 1.5, respectively) reliably distinguished those species carrying a high risk of invasiveness from those carrying a low to medium risk. For both the BRA and BRA+CCA, common lionfish Pterois miles was the highest-scoring species, followed by white perch Morone americana, red drum Sciaenops ocellatus, marbled spinefoot Siganus rivulatus and redcoat Sargocentron rubrum. The outcomes of this study will contribute to the management of non-native marine fish species for the conservation of the native ecosystems in the coastal waters of South Korea. •Out of 57 marine fish species assessed, 18 were classified as high risk.•45 species increased invasiveness risk by climate change assessment.•Climate change assessment resulted an increase in all very high risk species.•Standard errors indicated overall similarity in confidence levels and factors.