BackgroundReversing declining rates of people initiating and completing hepatitis C (HCV) treatment, observed in many countries, is needed to achieve global HCV elimination goals. Providing financial incentives to increase HCV testing and treatment uptake among people at-risk of or living with HCV infection could be an effective intervention. We conducted a systematic review to assess evidence regarding the effectiveness of financial incentives to improve engagement and progression through the HCV care cascade. MethodsWe searched MEDLINE, PubMed and EMBASE for studies published from January 2013 to January 2023 that evaluated financial incentives offered to people living with and at-risk of HCV to increase HCV antibody and or RNA testing, linkage to care, treatment initiation, treatment adherence, treatment completion, and sustained viral load (SVR) testing. Open-label randomised controlled trials (RCTs), controlled non-randomised studies, cohort or observation studies and mixed-methods studies were included, whereas literature reviews, case series and studies which did not report data were excluded. ResultsWe identified 1,278 studies, with 21 included after full-text screening (14,913 participants); three randomised controlled trials and 18 non-randomised studies. Studies evaluated incentives aimed at improving test uptake (n = 11), engagement in care (n = 13), treatment initiation (n = 8), adherence (n = 3), completion (n = 3) and attainment of SVR (n = 5). Findings provided inconclusive evidence for the effectiveness of incentives in improving engagement in the HCV cascade of care. Determining incentive effectiveness to improve care cascade engagement was limited by low quality study designs, heterogeneity in type (cash or voucher), value (US$5 to $600) and cascade stage being incentivised. No randomised controlled trials assessed the effectiveness of incentives to promote HCV testing, and none showed an impact on treatment uptake. In non-randomised studies (observational comparative), some evidence suggested that incentives promoted HCV testing, but evidence of their role in promoting linkage to care, HCV treatment adherence and treatment completion were mixed. ConclusionCurrently, there lacks high-quality evidence evaluating whether financial incentives improve HCV testing and treatment outcomes. Future research should seek to standardise methodologies, compare incentive types and values to enhance engagement in HCV care, and determine factors that support incentives effectiveness.