Background Migrants who have been forced to leave their home, such as refugees, asylum seekers, and internally displaced persons (IDP), are likely to experience stressors which may lead to mental health problems. The efficacy of interventions for mental health promotion, prevention, and treatment may differ in this population. Objectives With this overview of systematic reviews, we will map the characteristics and methodological quality of existing systematic reviews and registered systematic review protocols on the promotion of mental health and prevention and treatment of common mental disorders among refugees, asylum seekers, and IDPs. The findings from this overview will be used to prioritise and inform future Cochrane reviews on the mental health of involuntary migrants. Methods We searched Ovid MEDLINE (1945 onwards), Ovid Embase (1974 onwards), Ovid PsycINFO, ProQuest PTSDpubs, Web of Science Core Collection, Cochrane Database of Systematic Reviews, NIHR Journals Library, CRD databases (archived), DoPHER, Epistemonikos, Health Evidence, 3ie International Initiative for Impact Evaluation, and PROSPERO, to identify systematic reviews of mental health interventions for involuntary migrants. We did not apply any restrictions on date, language, or publication status to the searches. We included systematic reviews or protocols for systematic reviews of interventions aimed at refugees, asylum seekers, and internally displaced persons. Interventions must have been aimed at mental health promotion (for example, classroom‐based well‐being interventions for children), prevention of mental health problems (for example, trauma‐focussed Cognitive Behavioural Therapy to prevent post‐traumatic stress disorder), or treatment of common mental disorders and symptoms (for example, narrative exposure therapy to treat symptoms of trauma). After screening abstracts and full‐text manuscripts in duplicate, we extracted data on the characteristics of the reviews, the interventions examined in reviews, and the number of primary studies included in each review. Methodological quality of the included systematic reviews was assessed using AMSTAR 2. Main results The overview includes 23 systematic reviews and 15 registered systematic review protocols. Of the 23 published systematic reviews, meta‐analyses were conducted in eight reviews. It was more common for the search strategy or inclusion criteria of the reviews to state that studies involving refugees were eligible for inclusion (23/23), than for asylum seekers (14/23) or IDPs (7/23) to be explicitly mentioned. In most reviews, study eligiblity was either not restricted by participant age (9/23), or restricted to adults (10/23). Reviews commonly reported on studies of diagnosis or symptoms of post‐traumatic stress disorder or trauma (11/23) and were less likely to report on depression or anxiety (6/23). In 15 reviews the intervention of interest was focused on/ specific to psychological therapy. Across all 23 reviews, the interventions most commonly identified from primary studies were general Cognitive Behavioural Therapy, Narrative Exposure Therapy, and a range of different integrative and interpersonal therapies. Even though many reviews included studies of participants without a diagnosis of a mental health problem, they often assessed mental health treatments and did not usually distinguish between promotion, prevention, and treatment in the review aims. Together the 23 systematic reviews included 336 references, of which 175 were unique primary studies. Limitations to the methodological quality of reviews most commonly related to reporting of selection criteria (21/23), absence of a protocol (19/23), reporting of study design (20/23), search strategy (22/23), and funding sources of primary studies (19/23). Authors' conclusions Gaps exist in the evidence on mental health interventions for refugees, asylum seekers, and internally displaced persons. Most reviews do not specify that internally displaced persons are included in the selection criteria, even though they make up the majority of involuntary migrants worldwide. Reviews specific to mental health promotion and prevention of common mental disorders are missing, and there is more evidence available for adults or mixed populations than for children. The literature is focused on post‐traumatic stress disorder and trauma‐related symptoms, with less attention for depression and anxiety disorders. Better quality systematic reviews and better report of review design and methods would help those who may use these reviews to inform implementation of mental health interventions., Plain language summary An overview of systematic reviews on mental health interventions for involuntary migrants Refugees, asylum seekers, and internally displaced persons are involuntary migrants, who have often experienced distress when forced to leave their home, on the journey, and in the process of settling in a host country or new environment. Mental health promotion, prevention, and treatments for mental health problems such as depression, anxiety, and post‐traumatic stress disorder may work differently in these groups of people than for the general population. This overview of systematic reviews summarises the characteristics of reviews available on this topic, to help us determine which research questions are the most important to address in future Cochrane reviews. We searched for systematic reviews and protocols of systematic reviews on mental health promotion, prevention, and treatment of mental health problems for refugees, asylum seekers, and internally displaced persons. Mental health promotion may, for example, involve a classroom‐based well‐being intervention for children. An example of prevention is trauma‐focused therapy to prevent post‐traumatic stress disorder. Treatment may, for example, include psychological therapy for depression. We found 23 systematic reviews and 15 protocols of reviews in progress. Together the 23 published systematic reviews included 336 references, 175 of which were unique studies. Reviews more commonly included refugees and asylum seekers than internally displaced persons, and were more frequently focused on adults than children. There was more attention on the treatment of post‐traumatic stress disorder than there was for mental health promotion or prevention, or for the treatment of depression or anxiety. Studies of Cognitive Behavioural Therapy, Narrative Exposure Therapy, and integrative and interpersonal therapies were most likely to be included in reviews. The quality of reviews was limited by a range of issues, many of which related to poor reporting of the review methodology. The evidence available from systematic reviews may not match the need for evidence‐based interventions for the mental health of involuntary migrants. Review authors should consider relevant groups such as internally displaced persons, children, and people with depression or anxiety, and relevant interventions such as those for mental health promotion or prevention, and treatments other than psychological therapy.