As the burden of diabetes rises globally, countries are increasingly focused on national strategies for diabetes outcome evaluation and healthcare delivery. Clinical practice guidelines recommend a target glycated hemoglobin (HbA1c) of ≤7.0% for the majority of adults with diabetes. This cross-sectional observational study used a new database combining primary- and specialty care electronic medical records (EMR) to determine attainment of glycemic targets and associated predictors among adults with diabetes in Canada. The two data sources included: 1) Diabetes Action Canada’s National Diabetes Repository, containing deidentified EMR data from participating primary care providers in Ontario, Alberta, Manitoba, Québec, and Newfoundland, and 2) the LMC Diabetes Registry, containing deidentified EMR data from 13 diabetes specialty clinics in Ontario, Québec and Alberta. Among 122,106 adults with diabetes, target HbA1c of ≤7.0% was attained by 60% of adults with type 2 diabetes not prescribed insulin, 25% of adults with type 2 diabetes prescribed insulin, and 23% of adults with type 1 diabetes, demonstrating low attainment of glycemic targets. Potential contributors to suboptimal glycemic outcomes were sex, income, geographic location, and therapeutic inertia. Further work is required to understand and optimize outcomes with adults with diabetes, and to address factors contributing to glycemic outcome disparities.