This review aimed to summarize the evidence on the effectiveness of obesity prevention and treatment programmes for adolescents from socioeconomically disadvantaged backgrounds. A secondary aim was to identify potential successful intervention strategies for this target group. PubMed, EMBASE, PsycINFO and Cochrane Library were searched from January 2000 up to February 2016. Intervention studies targeting adolescents from disadvantaged backgrounds were included, with body mass index as outcome. Secondary outcomes were other adiposity measures, physical activity, diet, sedentary behaviour and screen time. Two independent reviewers extracted data, coded intervention strategies and conducted quality assessments. Fourteen studies were included: nine obesity prevention and five obesity treatment studies. Two preventive and four treatment studies showed significant beneficial effects on body mass index. Five of six studies (four preventive, one treatment studies) measuring dietary behaviour reported significant intervention effects. Evidence on other secondary outcomes was inconclusive. We found no conclusive evidence for which specific intervention strategies were particularly successful in preventing or treating obesity among disadvantaged adolescents. However, the current evidence suggests that involving adolescents in the development and delivering of interventions, the use of experiential activities and involvement of parents seem to be promising strategies. More high quality studies are needed. PROSPERO registration number: CRD42016041612.