Despite efforts to elucidate the relationship between traumatic event exposure and adverse mental health outcomes, our ability to understand why only some trauma-exposed individuals become emotionally affected remains challenged. The aim of the current study is to determine the relations between social support, religiosity, and number of lifetime traumatic events experienced on past-12 month posttraumatic stress disorder (PTSD), depression, and suicidal ideation (SI) in a nationally representative sample of Canadian Forces personnel. The current study used data from the Canadian Community Health Survey Cycle 1.2 – Canadian Forces Supplement. The impact of a number of predictive and mediating factors was assessed using structural equation modeling. Social support and number of lifetime traumatic events experienced were significant predictors of past-year PTSD, depression, and SI; however PTSD did not mediate the relationship between number of traumatic events and SI nor between social support and SI. Conversely, depression mediated the relationship between number of traumatic events and SI. Possible mechanisms for these findings and their implications are discussed.