Voluntary certification schemes and labels are used as a means to improve the sustainability of biomass feedstock production and biobased products. To ensure the viability of certification, it is important to understand its socioeconomic implications for certificate holders. Existing literature focuses on the economic impacts of certification within specific contexts (e.g., specific feedstock, regions, supply chain elements), and rarely addresses the social impacts. The present systematic literature review analyses the findings of 75 scientific articles covering the socioeconomic impacts of certification on producers of biobased feedstock (i.e. palm oil, maize, natural rubber, soybean, sugar cane, wood, and raw cotton) and related supply chains. The socioeconomic impacts are aggregated into 7 economic outcome categories (direct costs, indirect costs, revenues, income, productivity, price premiums, market access) and 5 social ones (health, education, poverty reduction, labour conditions, well-being). The results show that the economic impacts of certification are generally positive, with economic benefits compensating for the increased costs faced by companies after certification. Smallholders and companies located in low-income countries are more likely to experience negative economic impacts after certification because they have less access to resources for financing high upfront costs or legal documents on certification requirements, and face proportionally higher certification costs. The social impacts have been less investigated than the economic ones, and the results showed more mixed findings, although still mostly positive. Looking across the supply chain, both economic and social impacts were found to be investigated more for feedstock producers compared to other actors in the supply chains. New policy should focus on mitigating the negative impacts on vulnerable groups to improve their participation in certification programmes.