Objectives: In Canada, non-communicable diseases account for 88% of all deaths, most of which could be prevented through a healthier diet, regular physical activity (PA), smoking cessation, and reduced alcohol consumption. This study aims to estimate the number of deaths that could be prevented or delayed if (1) the average behaviors of Canadians aligned with recommendations for healthy behaviors, or if (2) the average behaviors of Canadians equaled those of residents in the provinces with the healthiest behaviors. Methods: We used the Preventable Risk Integrated Model macrosimulation model to estimate the number of deaths that could be prevented through population-level behavioral changes. Information on Canadians’ health behaviors was obtained from the most recent edition of the Canadian Community Health Survey (2015), which reported diet (from 20 487 participants) as well as PA, alcohol consumption, smoking, and sedentary time (from 110 095 participants). Age-specific and gender-specific mortality data for 2015 were obtained from Canadian Vital Statistics, and 95% uncertainty intervals (UI) were calculated through Monte Carlo analyses. Results: Following behavioral recommendations could have prevented 30 756 deaths (95% UI, 25 867 to 34 965) in 2015. Improving Canadians’ lifestyles to match the behaviors of the healthiest provinces could have prevented 6758 deaths (95% UI, 5062 to 8382). Improvements in fruit and vegetable intake alone could have prevented most of these deaths. Most preventable deaths were attributed to cardiovascular diseases. Conclusions These findings show that even modest, realistic lifestyle improvements at the population level could substantially reduce the burden of chronic disease in Canada.