Background:There is evidence to suggest that the experience of C-PTSD may be commonly associated with elevated risk of several mental ill health related comorbidities. The current study seeks to contribute to the growing literature on C-PTSD comorbidity by examining the relationship between C-PTSD diagnosis and mental ill health outcomes (Suicidality, Depression and Generalised Anxiety) in a UK Armed Forces military veteran sample. Method: This study utilised data from the Northern Ireland Veterans Health & Wellbeing Study (NIVHWS). The NIVHWS is a cross sectional survey measuring several outcomes among 1329 veterans based in Northern Ireland. The effective sample consisted of 638veterans (90.0% male). Logistic regression analyses examined probable C-PTSD diagnosis as a predictor of several other mental health outcomes. LCA was then conducted determine the correct number and nature of classes within the sample in relation to C-PTSD, depression, anxiety and suicidality. Results: C-PTSD caseness (probable diagnosis) was found to be a significant predictor of all other mental health outcomes under investigation. Overall, four latent classes emerged, with each of these classes characterised by varying degrees of co-morbidity: a ‘Low Comorbidity’ class, a ‘Moderately Suicidal’ class, ‘Depression- Anxiety’ class and a ‘High Comorbidity’ class. Conclusion: These findings support and extend those previous which indicate the highly comorbid nature of C-PTSD. C-PTSD may be considered a highly co-morbid and poly-morbid condition increasing the risk for multiple mental health pathologies concurrently.