Based on stakeholder agency theory, this structured literature review included 89 empirical quantitative studies published between 2013 and the present on the complex relationship between financial auditors and corporate social responsibility (CSR) outcomes. We created a research framework based on DeFond and Zhang’s (2014) taxonomy and the bi-directional differentiation between the incentives and competencies of financial auditors. CSR outcomes were further divided into CSR performance, reporting, and assurance. We found that audit fees and big four audit firm involvement increased the level of CSR outcomes in many studies, and that CSR performance was negatively related to audit fees. The link between financial auditors and CSR assurance (quality, scope, and provider) represents the primary research gap. Future researchers should measure the effect of the sustainability expertise of financial auditors on CSR outcomes and the concrete conditions under which a joint provision of financial audit and CSR assurance leads to increased CSR.