Although Canada possesses abundant freshwater resources, uneven water distribution, rapid climate change, deteriorating source water quality, and insufficient water infrastructure put small, rural, and remote (SRR) communities at a risk of water advisories and waterborne disease that is 26 times higher than in cities. Approximately three-quarters of SRR communities are Indigenous, indicating that they are more likely to experience water insecurity than non-Indigenous communities. This review examines key factors exacerbating water insecurity in SRR communities, including: (i) the types and ranges of commonly detected contaminants in source water, (ii) contaminant pathways and associated health risks, and (iii) the performance and challenges of small water systems (SWSs) in Canadian SRR communities. Total coliforms and E. coli in the microbiological category, and arsenic, lead, and manganese in the heavy metals and trace minerals category, had the highest number of occurrences among contaminants reported in dedicated studies. In contrast, fewer studies have investigated contaminants of emerging concern (CECs) and the capacity of SWSs to remove them. Common SWSs such as, multistage sand filtration, roughing filtration, granular activated carbon, chlorination, and ozonation offer relatively simple and affordable decentralized options; however, their long-term performance, operation, maintenance, governance, and social acceptability remain challenging.