ABSTRACTBackground:Timely and effective interventions can alleviate or prevent the development of clinical symptomatology in trauma-exposed individuals. However, due to limited access to these interventions, and/or stigma around accessing mental health services, there is an unmet need. Internet-and mobile-based interventions may help to address this need.Aims:This review aims to (i) synthesise the evidence on feasibility, acceptability, and effectiveness of the ‘PTSD Coach’ intervention (both web-based and mobile applications) in trauma-exposed individuals; (ii) evaluate the quality of this research; and (iii) identify challenges and recommendations related to ‘PTSD Coach’ intervention delivery.Method:Systematic database searches were conducted (PubMed/MEDLINE, PsycINFO, EMBASE, PLoS, Web of Science, PTSDpubs, Scopus, and clinical trial databases). Review inclusion was based on predefined inclusion criteria, and study quality was assessed with the mixed methods appraisal and the risk-of-bias tools for randomised trials. Where feasible, meta-analytical pooling of intervention effects on posttraumatic stress symptoms (PTSS) was conducted.Results:Seventeen manuscripts reporting on 16 primary studies were included with the majority evaluating a self-managed PTSD Coach mobile application intervention. Most studies were conducted in higher-income countries and females were over-represented. For both platforms, satisfaction and perceived helpfulness were generally high but type of smart device operating system was identified as an influence. The pooled effect size in symptom severity in the intervention group compared to the comparison group was not significant (standardised mean difference =  – 0.19) (95% CI − 0.41 to − 0.03,p= .09). Heterogeneity was not significant (p= .14; I2 =40%). No study was excluded based on quality assessment.Conclusion:Findings support the feasibility and acceptability of ‘PTSD Coach’ in trauma-exposed individuals. However, evidence on the effectiveness on PTSS remains limited. More research is still needed in low-middle-income countries, particularly those in which supported ‘PTSD Coach’ interventions are evaluated in larger and more diverse samples.