Increasing evidence highlights the relevance and frequent consideration of fetal alcohol spectrum disorder (FASD) in Canadian criminal legal cases, though systematic evaluation of the impact of such evidence on legal outcomes remains limited. We sought to fill this gap via a systematic review of reported Canadian criminal cases mentioning evidence of FASD (including prenatal alcohol exposure, PAE) between 2012 and 2020. The final sample of 350 cases primarily included male (92.3%) adult defendants (86.9%). The majority focused on sentencing determinations (76.3%), along with dangerous/long-term offender (DO/LTO) designations (1.4%), guilt/innocence (3.4%), criminal responsibility (0.8%), fitness to stand trial (0.6%), and other decisions (7.4%). Indigenous defendants were overrepresented (76.9%), with a subset of cases (33.1%) addressing FASD evidence alongside Gladue sentencing considerations, findings that must be situated in the context of systemic inequities and colonization. Often, evidence about FASD was mentioned only once (42.3%), and roughly half of the cases referenced a formal FASD diagnosis (53.1%). Evidence about FASD was assessed as having “great relevance” in 21.7% of decisions, and among these cases, there was relative consensus that FASD can reduce a defendant’s responsibility and moral blameworthiness, and general acceptance as a mitigating factor. However, decision-making challenges were evident across cases due to competing concerns about risk, public protection, rehabilitation, and the long-term nature of the disability. Findings highlight the importance of improving evidence-based FASD knowledge, increasing access to evidence-informed resources, and bringing a culturally informed lens that highlights Indigenous ways of knowing when working within the criminal legal system.