Housing First (HF) models have gained popularity among many politicians, policy-makers, and social service providers. Proponents of this model argue for its strength by drawing on research evidence. In other words, the use of HF is deemed an ‘evidence-based practice.’ Despite this, a strong synthesis of the evidence used to champion these models is lacking. This article seeks to address this gap, with a review focused on outcomes associated with participation in HF programs. Specifically, we investigate the details of program design coupled with specific outcomes, so as to better inform future action and research. We conclude that the research forming the evidence base for HF is methodologically strong. However, additional research is needed to determine the benefits of HF for diverse populations. Additional research is also required to conclusively determine the impact of HF on substance use and psychiatric treatment. We recommend that policy-makers consider the needs of local populations when developing and implementing HF programing.