IntroductionAsylum seekers and refugees are at an elevated risk of self-harm, with younger age and traumatic experiences found to further increase such risk. Despite this, evidence regarding self-harm among unaccompanied asylum seekers and refugee minors has not been synthesised. As self-harm among minors is a risk factor for a range of adverse clinical and social outcomes, including suicide, such information may help to inform evidence-based prevention strategies among these vulnerable populations. This systematic review will synthesise findings from the literature regarding the prevalence, methods and characteristics of self-harm, including risk and protective factors, among unaccompanied asylum seekers and refugee minors internationally.Methods and analysisWe searched key electronic databases (PsycINFO, Scopus, PubMed and Ovid MEDLINE) and grey literature for relevant studies published in English from database inception to 10 February 2023. Our primary outcome is self-harm among unaccompanied asylum seekers and/or refugee minors. With the exception of single-case studies, clinical trials and case-control studies, we will include all types of study design that examine the prevalence of self-harm in unaccompanied asylum seekers and/or refugee minors. We will exclude dissertations, conference abstracts, letters, book chapters, editorials, study registrations, registered protocols and qualitative studies. Only studies reporting on participants aged <18 years will be eligible for inclusion. The Methodological Standard for Epidemiological Research Scale will be used to assess the quality of included studies. If there are sufficient studies and homogeneity between them, we will conduct meta-analyses to calculate pooled estimates of self-harm rates, as well as comparisons between subgroups of relevance. If the studies do not report sufficient data, or there is substantial heterogeneity, we will provide a narrative synthesis of the findings.Ethics and disseminationThis review is exempt from ethics approval. Our findings will be disseminated through peer-reviewed publications and conference presentations.PROSPERO registration numberCRD42021292709.