Financing human service delivery through social impact bonds (SIBs) is the subject of some critical commentary in the academic literature, but this tends to be largely theoretical rather than empirically based. This paper presents empirical evidence of how SIB financing can promote positive social and economic outcomes for governments, not‐for‐profit providers, individual service beneficiaries and society more broadly. The paper presents some of the results of an evaluation of the Aspire SIB, which financed an innovative intensive case management program providing housing and wraparound supports over a 3‐year period for people experiencing chronic homelessness. Aspire participants experienced significantly improved outcomes and decreased service needs, delivering downstream cost savings across several areas of government service delivery. This paper describes how the SIB financing mechanism underpinned the success of Aspire by promoting flexible, collaborative, outcome‐focussed and data‐informed responses to a challenging, multi‐faceted social problem.