How to best serve criminal offenders who have mental health issues is of ongoing concern within the justice system in Canada. Mental health diversion has become a popular option that allows mentally disordered offenders to be diverted from custodial sentences to community treatment and supports. However, research on this type of intervention, particularly in Canada, is scant. In order to address this gap, the current set of studies examined mental health diversion in a multisite sample obtained from court support programs in the Greater Toronto Area. In Study 1, it was found that individuals who successfully completed their diversion programming were less likely to have a criminal history and had fewer clinical and psychosocial issues. These results were borne out in the multivariate analyses in Studies 2 and 3 as well, with individuals who had a criminal history, more clinical needs, and who committed more severe nonviolent index offences having lower odds of successfully completing their diversions. In Study 4, when these predictors were developed into a screening tool to determine the likelihood of diversion success, they still predicted diversion outcome at better than chance levels, but the overall predictive accuracy was lower than that found in the multivariate models from Study 3.