Campylobacter jejuni is the leading cause of gastroenteritis in the developed world, with human infections predominantly acquired via under-cooked or poorly prepared poultry, a host in which the organism is considered a commensal. C. jejuni encodes a protein N-glycosylation system (Pgl), which targets >100 membrane-associated proteins and is required for both human infection and chicken colonization. Despite this, the exact biological role of this post-translational modification system remains poorly understood. We employed iTRAQ-based labelling to show that loss of the PglB oligosaccharyltransferase (ΔpglB), or biosynthetic enzymes that generate the glycan (ΔpglDEF), have a limited effect on whole protein abundance relative to wild-type. Changes were largely associated with known glycoproteins, with ~17% of quantified N-glycoproteins displaying altered protein abundances. N-terminal amine isotopic labelling of substrates (N-TAILS) comparisons between wild-type and Δpgl mutants provided evidence for proteolytic processing in close proximity to known sites of N-linked glycosylation that was only identified in pgl mutant strains. We next performed intact glycopeptide analysis of N-glycopeptide enriched membrane protein fractions from wild-type C. jejuni, using protein level dimethylation to differentiate those N-glycopeptides localised at protein N-termini. Using this approach, we were able to identify 78 unique C. jejuni N-glycopeptides, including 2 novel sites. We also provide evidence that the proteolytic activity associated with sites of N-glycosylation is limited in the wild-type, further supporting the conclusion that N-glycosylation serves to protect N-glycoproteins from proteolytic degradation within the C. jejuni membrane.