Mindfulness is characterized by skills such as heightened awareness and acceptance of internal experiences, which may be helpful for people who have experienced trauma. The consistency and strength of the relationship between trait mindfulness and PTSD symptomology, however, is unknown. Studies were included in this review if they were published in an English language peer-reviewed journal, reported on a correlational relationship between validated measures of mindfulness and PTSD, and all participants were over the age of 18. A random effects meta-analysis showed that there was a robust, pooled relationship between total mindfulness and PTSD (r+ = -0.39, 95% CI [-0.47 to -0.30]), based on 35 datasets with 13,370 participants, with low risk of publication bias. Sixteen articles reported on facets of mindfulness and PTSD symptomology [5,206 to 5,600 participants]: the strongest associations were with Act with Awareness (r+ = -0.37) and Non-judge (r+ = -0.37), followed by Describe (r+ = -0.22) and Non-react (r+ = -0.21). Observe was not significantly associated with PTSD symptoms. Results from this analysis suggest that people who are more mindful also report fewer symptoms of PTSD ; the strength of the relationship varies across mindfulness facets. There was high heterogeneity across studies.