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). 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. 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. 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.