There has been a significant development of digital interventions for the treatment of Post-Traumatic Symptom Disorder (PTSD) over the past two decades. However, the majority of research has examined their clinical efficacy for military service members and veteran populations whereas community-based trauma survivors have received significantly less attention. Their effectiveness for this population, therefore, remains unclear. The aim of this review was to evaluate the effectiveness of digitally delivered psychological therapies to alleviate PTSD symptomatology in the general population. Findings showed that digitally delivered Cognitive Behavioural Therapy (iCBT) produced more consistently significant improvements in PTSD symptoms, compared to interapy, expressive writing, psychoeducation, mindfulness, cognitive tasks and psychosocial interventions. iCBT - associated improvements were also independent of the focus (i.e. trauma vs. non-trauma) of the intervention, the provision of therapeutic support (e.g. guided vs. unguided), type of feedback (e.g. automated vs. individualised) or the number of sessions provided. Nevertheless, the number of included studies for subgroup analyses was relatively low. Digital interventions have an enormous potential to improve accessibility, efficiency, clinical effectiveness and personalisation of mental health interventions. Future research is needed to investigate further the use of a wider range of therapeutic approaches across different clinical and subclinical groups and settings and test the impact of these interventions (or components) against a wider range of comparison conditions (e.g. face to face CBT) with optimal power.