To evaluate current levels of physical activity and sedentary behaviour among pregnant and non-pregnant adults in Canada.We ascertained population-based cross-sectional data from the Canadian Community Health Survey (CCHS), 2015-2019, and from the Canadian Health Measures Survey (CHMS), 2007-2019. We included adults who were assigned female at birth and of reproductive age (ages 18-55) living in the provinces. We analyzed activity data from validated questionnaires and accelerometers.We included 53 765 adults from the CCHS and 5321 from the CHMS, weighted to represent 16 million people. Based on accelerometers, both pregnant and non-pregnant adults spent 9.5 hours per day (70% of their time) engaged in sedentary behaviour. Across all survey years, ages, and Canadian regions, pregnant adults, especially those under 35 years old, spent less time engaged in moderate-to-vigorous physical activity (MVPA) compared to non-pregnant adults. Pregnant adults reported 34.3 minutes (95% CI 30.5-38.2) and objectively accrued 14.9 minutes (95% CI 7.9-21.8) in MVPA per day - 15.1 and 8.9 fewer minutes compared to non-pregnant adults, respectively. After accounting for self-report bias, only 27.5% (95% CI 24.1-31.0) of pregnant and 41.1% (95% CI 40.4-41.9) of non-pregnant adults met the Canadian physical activity guidelines (i.e., ≥ 150 minutes of MVPA per week).Physical activity levels are remarkably low among both pregnant and non-pregnant adults, with few meeting current guidelines. Given the substantial physical and mental health benefits, more supports are needed to increase pre-pregnancy and prenatal activity in Canada.