The major human pathogen Staphylococcus aureus possesses ten extracellular proteases that are central to the virulence process. While some host targets of these and other bacterial proteases are known, a major bottleneck to the study of their function is the low-throughout nature of substrate identification. Rapid identification of proteolytic cleavage events in complex substrates has, however, been rendered possible by recent developments in the proteomics sub discipline of N-terminomics. Thus, herein we perform the first study of bacterial protease-host interactions, combining the S. aureus V8 protease and the infection relevant substrate human serum. In so doing, we identified ~90 host-protein targets of V8, including previously known and novel targets. Amongst these were complement components (C1r, C1s, C3,C4b, C4BPA, C5, C6, C8G, C9, CfB, CfH, and ficolin), iron sequestration and transport proteins (ceruloplasmin, serotransferrin, hemopexin, haptoglobin), clotting cascade proteins (plasminogen, kallikrein proteins, prothrombin, factors X and XII), and multiple host protease inhibitors (α2M and members of the ITIH and SERPIN families). N-terminomics also provided insight into the disruption of host protein function by highlighting specific target regions of host proteins, where V8 cleaved within peptidase and sushi domains of complement proteins, and, in the case of host protease inhibitors, cleavage occurred predominantly outside their protease-trapping motifs. Collectively, our data highlight the potential for further application of N-terminomics for the discovery of bacterial protease substrates in other host niches, and provides unique insight into the role of the V8 protease in S. aureus pathogenesis.