Background: Physical activity and sedentary behaviors are major determinants of quality of life in adults with one or more chronic disease(s). However, there are no Canadian representative population-based studies investigating objectively measured physical activity and sedentary behaviors in adults with and without chronic disease(s). Objective: To compare objectively measured physical activity and sedentary behaviors in a representative sample of Canadian adults with and without chronic disease(s). Methods: Data were obtained from the Canadian Health Measure Survey (CHMS) (2007-2013). Physical activity and sedentary behaviors were measured using accelerometry in Canadians aged between 35 and 79 years. Data are characterized as daily mean time spent in moderate to vigorous physical activity (MVPA), light physical activity (LPA), and sedentary behavior, as well as steps accumulated per day. Chronic diseases (chronic obstructive pulmonary disease, diabetes, heart diseases, cancer) were assessed via self-report diagnostic or laboratory data. Four weighted multivariable analyses of covariance comparing physical activity and sedentary behavior variables among adults without and with one or more chronic diseases were conducted. Results: In the total, 6270 CHMS participants were included. Analyses indicated that 23.9%, 4.9% and 0.5% had one, two, and three or more chronic diseases. Adults with two or three and more chronic diseases had significantly lower daily duration of MVPA and LPA, lower daily step counts, and higher daily duration of sedentary behavior compared to adults with no chronic diseases, with low effect sizes. Conclusions: Canadian multimorbid adults might benefit from targeted interventions to increase physical activity and reduce sedentary behaviors.