In 1997, Canada's youth custodial facilities held 3825 sentenced youths. Eighteen years later, this number was 527—an 86 percent reduction. Overall youth imprisonment (sentenced + pretrial detention) decreased by approximately 73 percent. This paper uses Canada's successful decarceration of youths to understand what might be learned about decarceration more broadly. By examining the reforms that transpired in Canada's treatment of young offenders since the 1960s and the political/cultural shifts that occurred since the 1990s, we demonstrate that the decline resulted from changes occurring in various parts of the system. Finally, we contrast this decarceration with more than 60 years of relative stability of Canadian adult imprisonment rates as well as Canada's failure to substantially decrease youth pretrial detention in order to identify those factors seemingly necessary to reduce imprisonment more generally.