Several psychosocial interventions have shown promising effects in treating people affected by childhood maltreatment (CM); however, their comparative efficacy on social functioning remains largely unknown. To address this issue, a systematic review and network meta-analysis (NMA) will be conducted to investigate the comparative efficacy of different psychosocial interventions on global social functioning and specific domains of social functioning, including behavioural, emotional, cognitive and physiological processes. We aim to develop a hierarchical ranking of existing psychosocial interventions concerning their efficacy and acceptability which could inform treatment guidelines. Randomised controlled trials (RCTs) investigating psychosocial interventions for individuals with exposure to CM when they were younger than age 18 will be included. Primary outcomes will be global and domains of social functioning (measured up to 3, 6, 12 months and at the longest follow-up). Study drop-out will be a secondary outcome that will serve as a measure of acceptability. Study selection and data extraction will be performed by at least two independent reviewers. We will assess the risk of bias for each study using the Cochrane Risk of Bias tool 2 (RoB2) and evaluate the confidence in the results using Confidence in Network Meta-Analysis (CINeMA). The effects of potential moderators, such as age (children/adolescents adults), population type (clinical non-clinical samples), or sex (% males), socioeconomic status (low-income middle-high-income countries), and intervention characteristics (individual group training, number of sessions) will be analysed using subgroup-analyses or meta-regressions. Other candidate moderators/mediators (personality, post-traumatic symptoms, brain structure/function, cognitive reserve) will also be explored and narratively summarised. Sensitivity analyses will be conducted to explore further heterogeneity and assess the robustness of our findings. This systematic review and NMA aims to compare multiple existing psychosocial interventions in individuals affected by CM and establish the relative rankings of these interventions for social functioning. Our results may provide practical guidance concerning the most effective psychosocial interventions to reduce the societal burden associated with CM. PROSPERO CRD42022347034.