Fish represent a key economic, social and ecological group of species that humans have exploited for tens of thousands of years. However, as many fish stocks are going into decline and with little known about the anthropogenic impacts on the health of the marine ecosystem pre-Industrial Revolution, understanding historical and archaeological exploitation of fish species is key to accurately modelling these changes. Here, we explore the potential of collagen peptide mass fingerprinting (also known as Zooarchaeology by Mass Spectrometry, or ZooMS) for identifying fish remains from the Medieval (fifteenth century) Newport ship wreck (Wales, UK), and in doing so we establish a set of biomarkers we consider useful in discriminating between European fish taxa through the inclusion of over 50 reference taxa. The archaeological results identified nine distinct taxonomic groups, dominated by ling (> 40%), and a substantial amount of cod (> 20%) and hake (similar to 20%). The vast majority of samples (> 70%) were identified to species level, and the inability to identify the remaining taxonomic groups with confidence using ZooMS was due to the fact that the reference collection, despite being relatively large in comparison to those presented in mammalian studies, reflects only a small proportion of fish biodiversity from this region. Although the results clearly demonstrate the potential for ZooMS as a means of fish bone identification, the sheer number of different fish species that potentially make up ichthyoarchaeological assemblages leads to obvious requirements for the analysis on much greater numbers of modern reference specimens, or the acquisition of collagen sequences.