Objectives <p>Asthma is a common respiratory disease in Canada, representing a significant burden on the health of the population and the healthcare system. While studies have attributed an association between obesity and asthma, understanding of this relationship remains underexplored in the Canadian population. This study aims to describe the association between BMI and current asthma in adults living across Canada.</p> Methods <p>This study used cross-sectional data from the 2017–2018 Canadian Community Health Survey of individuals aged 18&#xa0;years and older who reported currently having asthma. Current asthma was defined as having been previously diagnosed with asthma and experiencing asthma symptoms or asthma attacks in the past 12&#xa0;months. Prevalence ratios (PRs) and 95% confidence intervals (CIs) were estimated using log-binomial regression, modelling the association between BMI (underweight/normal weight (&lt; 25&#xa0;kg/m²), overweight (25– &lt; 30&#xa0;kg/m²), and obese (≥ 30&#xa0;kg/m²)) and current asthma, adjusting for relevant sociodemographic and health factors.</p> Results <p>Of the 7090 individuals with asthma in this study, 3627 (51.2%) experienced current asthma. The prevalence of current asthma was similar in overweight individuals (PR = 1.00, 95%CI 0.95, 1.05) when compared to those in the underweight/normal weight category, while individuals with obesity had a 5% higher prevalence (PR = 1.05, 95%CI 1.01, 1.10) when compared to those in the underweight/normal weight category.</p> Conclusions <p>This study provides evidence for the association between obesity and an increased prevalence of current asthma among adults. Weight management, particularly for individuals with obesity, may be an important consideration in asthma control.</p>