IMPORTANCE: The Canadian Occupational Performance Measure (COPM) is widely used in clinical practice and research. However, the measurement properties of the COPM were not reviewed using rigorous systematic methodology. OBJECTIVE: To evaluate the measurement properties of the COPM. DATA SOURCES: MEDLINE, Web of Science, Scopus, OTseeker, and Cochrane Library. Study Selection and Data Collection: We used the updated COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) Risk of Bias checklist to evaluate the measurement properties of the COPM reported in relevant studies. FINDINGS: Our search identified 35 articles that reported measurement properties for the COPM with samples that differed in age, country, diagnosis, and disease stage. For content validity, the evidence was inconsistent and of low quality; no studies assessed structural validity. For reliability, the internal consistency was indeterminate and of low quality. One study reported indeterminate and very low quality evidence for cross-cultural validity. According to the evidence reported in these studies, the COPM has inconsistent and moderate reliability, construct validity, and responsiveness and insufficient and high-quality evidence for criterion validity. CONCLUSIONS AND RELEVANCE: Our review of the evidence using the COSMIN Risk of Bias checklist indicates that the Canadian Occupational Performance Measure lacks high-quality validation. What This Article Adds: High-quality validation of the Canadian Occupational Performance Measure is lacking. Further examination of its measurement properties using updated relevant guidelines is required.