People who experience mental ill-health are typically more disadvantaged across a range of social and economic domains compared with the general population. This disadvantage is further heightened for people from marginalised communities. Social and economic adversities can limit both the access to, and effectiveness of, interventions for mental ill-health; however, these challenges are often overlooked by mental health services. Therefore, adequate support for social needs is urgently required, particularly for those from marginalised and vulnerable groups. We conducted a PRISMA-compliant systematic review of three academic databases to identify social and/or economic interventions which were adapted or developed bespoke for people from marginalised or minoritised communities living with mental ill-health. All records were screened blind by two reviewers; quality appraisal was conducted with the Kmet tool. Seventy-eight papers were included, deriving mostly from high-income countries. The identified interventions targeted nine sociodemographic or socioeconomic groups including: people experiencing homelessness or unstable housing (n = 50), people with an offending history (n = 9), mothers (n = 6), people experiencing economic disadvantage (n = 3), older adults (n = 3), caregivers (n = 2), minority ethnic groups (n = 2), women with experience of intimate partner violence (n = 1), and people with comorbid intellectual disabilities (n = 1). All identified interventions demonstrated feasibility, acceptability, or effectiveness on at least one social and/or economic outcome measure, suggesting that targeted intervention can help to address social and economic needs and reduce systemic inequalities in mental health care. However, the evidence base is still sparse, and further replication is warranted to inform commissioners and policy makers.