BackgroundDespite primary care being largely free at the point of delivery, many Canadians experience challenges in accessing the services they need. A systematic review was conducted to summarize the evidence on the level of unmet need for primary care in Canada and its social determinants.MethodsMEDLINE, Embase, Cochrane, and Web of Science databases were screened from inception to December 2023 using relevant search terms for primary care and unmet healthcare needs. Quantitative observational studies in the English language that included Canadian adults aged 18 years and older and focused on unmet needs for primary care were included. The risk of bias in the studies was assessed using either the Joanna Briggs Institute (JBI) critical appraisal checklist or the Newcastle–Ottawa Scale. The included studies were synthesized narratively.ResultsForty-six studies met the inclusion criteria for this review. Of the included studies, 96% were cross-sectional in design and 91% had low risk of bias. The prevalence of unmet need, mostly self-reported, varied between 6.6% and 25.2% in national studies. Social determinants of unmet needs were heterogeneous across studies. Findings suggest that unmet need for primary care is related to having low income, mental health diagnoses, and chronic conditions, and negatively associated with older age, having better-perceived health, and having a family physician.ConclusionsUniversal access to primary care is the founding principle of the Canadian healthcare system. However, we found evidence suggesting that the extent to which primary care needs are met is influenced by social determinants of health. Further research is needed to improve our understanding of the mechanisms of unmet primary care needs in Canada.Systematic review registrationPROSPERO CRD42021285074.