Aboriginal overrepresentation in the criminal justice system is one of the clearest markers of what the Supreme Court of Canada has referred to as “a crisis in the Canadian justice system.” Aboriginal overrepresentation is often thought of as a problem in western Canada but, in fact, Ontario ranks third in terms of overrepresentation across the country. [...] In particular, the paper will focus on the 1996 amendments to the sentencing provisions of the Criminal Code and the decision of the Supreme Court of Canada in 1999 in R. v. Gladue1 that gave the section renewed vigour and power. [...] In the context of a discussion of Aboriginal overrepresentation in prison the court stated the case quite dramatically: “These findings cry out for recognition of the magnitude and gravity of the problem, and for responses to alleviate it. [...] In order to draw any conclusions regarding overrepresentation of any group in the criminal justice system, two pieces of data are required: first, the percentage of the particular group of the overall population, and second, the proportion of the group among those in the criminal justice system. [...] While the fact of Aboriginal over-incarceration had been known for some time, it was the publication of “Locking Up Natives In Canada: A Report of the Committee of the Canadian Bar Association on Imprisonment and Release” in 1988 that really brought the issue to the fore.