People with disabilities-more than a billion people worldwide-are frequently excluded from social and political life, and often experience stigmatising attitudes and behaviours from people without disabilities. This stigma, coupled with inaccessible environments and systems and institutional barriers (e.g., lack of inclusive legislation), may result in discrimination against people with disabilities (and their families) to the degree that they are not able to enjoy their rights on an equal basis with others. This review examines the effectiveness of interventions for improving social inclusion outcomes (acquisition of skills for social inclusion, broad-based social inclusion, and improved relationships) for people with disabilities in low- and middle-income countries (LMICs). We searched academic and online databases, carried out citation tracking of included studies, and contacted experts to ensure our search was as comprehensive as possible. We also ran the searches with search terms specific to social inclusion review using Open Alex in EPPI reviewer. We included all studies which reported on impact evaluations of interventions to improve social inclusion outcomes for people with disabilities in LMIC. We used review management software EPPI Reviewer to screen the search results. Two review authors independently extracted the data from each study report, including for the confidence in study findings appraisal. Data and information were extracted regarding available characteristics of participants, intervention characteristics and control conditions, research design, sample size, risk of bias and outcomes, and results. Random-effects inverse variance weighted meta-analytic methods were used to synthesise standardised mean differences for the outcomes. We identified 37 experimental and quasi-experimental studies. Studies were conducted in 16 countries, with the majority of the included studies (n = 13) from South Asia and nine each from East Asia, the Pacific, the Middle East, and North Africa. Most studies targeted children with disabilities (n = 23), and 12 targeted adults with disabilities. Most focused on people with intellectual disabilities (n = 20) and psychosocial disabilities (n = 13). Regarding intervention content, most (n = 17) of the included programmes aimed to improve the social and communication skills of people with disabilities through social skills training programmes. Ten studies aimed at providing personal assistance and support and evaluated the effects of a parent training programme on the interactive skills of parents of children and their children with disabilities. We calculated effect sizes from experimental and quasi-experimental studies for outcomes on skills for social inclusion, relationships of people with disabilities with family and community members, and broad-based social inclusion among people with disabilities. A meta-analysis of 16 studies indicates an overall positive, statistically significant and large effect of the interventions for skills for social inclusion with standardised mean difference (SMD) = 0.87, confidence interval (CI) = 0.57 to 1.16, k = 26, I 2 = 77%, p < 0.001). For relationships across 12 studies, we find a positive but moderate effect (SMD = 0.61, CI = 0.41 to 0.80, k = 15, I 2 = 64%, p < 0.01). As for the overall effect on broad-based social inclusion, we find the average effect size was large, and there was significant dispersion across studies (SMD = 0.72, CI = 0.33 to 1.11, k = 2, I 2 = 93%, p < 0.01). Despite the significant and large effects estimated by the studies, some limitations must be noted. Although there was a consensus on the direction of the effects, the studies presented considerable heterogeneity in the size of the effects. A majority (n = 27) of studies were assessed to be of low confidence related to methodological limitations, so the findings must be interpreted with caution. Tests for publication bias show that the effect sizes of social skills (p < 0.01) and social inclusion (p = 0.01) are all likely to be inflated by the existence of the publication bias. The review's findings suggest that various interventions to improve the social inclusion of people with disabilities have a significant positive effect. Interventions such as social and communication training and personal assistance led to significant improvement in the social behaviour and social skills of people with disabilities. Studies targeting broad-based social inclusion showed a large and significant positive effect. A moderate effect was reported from interventions designed to improve relationships between people with disabilities and their families and communities. However, the findings of this review must be interpreted cautiously, given the low confidence in study methods, severe heterogeneity and significant publication bias. The available evidence focused primarily on individual-level barriers such as interventions for improving social or communications skills of people with disabilities and not the systemic drivers of exclusions such as addressing societal barriers to inclusion, such as stigma reduction, and interventions to strengthen legislation, infrastructure, and institutions.