Introduction:This study conducted a systematic review and meta-analysis of the association between posttraumatic stress disorder (PTSD) and (i) death by suicide, (ii) attempted suicide (AS), and (iii) suicidal ideation (SI). Methods:The systematic review identified seven studies on PTSD and suicide, 33 studies for AS, and 20 studies for SI. A series of stratified meta-analyses were conducted to estimate pooled effects, in addition to meta-regression to investigate sources of heterogeneity.Results: A higher relative risk of suicide was evident among those diagnosed with PTSD (RR = 2.09 [95% confidence interval (CI): 1.11-3.94]), with strongest associations among combat veterans (RR = 3.97, 95% CI 2.22-7.10). A lower relative risk of suicide among those with PTSD and co-morbid psychiatric conditions was evident (RR = 0.74, 95% CI 0.63-0.86). A strong association between PTSD and attempted suicide (RR = 4.05, 95% CI 3.14-5.23) and suicidal ideation (RR = 2.91, 95% CI 2.22-3.82) was also found, with a consistently strong association among those with co-morbid psychiatric conditions and non-clinical cohorts. Conclusion:This review found a strong association between PTSD and death by suicide, attempted suicide, and suicidal ideation, and also suicide among veteran populations. Early identification and treatment of PTSD across both clinical and non-clinical cohorts should be a priority for suicide prevention.