BACKGROUND: Physical activity, sufficient sleep, and limiting sedentary time may improve cancer survivorship. METHODS: Utilizing US nationally representative samples from the National Health Interview Survey 1997-2018 and the National Health and Nutrition Examination Survey 2007-2018, this study investigated the trends of meeting physical activity guidelines, insufficient sleep duration, and sitting time in US cancer survivors (n = 58 527) and noncancer adults (n = 640 109). RESULTS: From 1997 to 2018, the prevalence of meeting physical activity guidelines was consistently lower in cancer survivors than in noncancer adults. Among cancer survivors, the prevalence of meeting physical activity guidelines increased from 34.9% (95% confidence interval [CI] = 33.1% to 36.8%) to 46.5% (95% CI = 45.0% to 48.1%) for aerobic (≥150 minutes per week at moderate intensity or 75 minutes per week at vigorous intensity), from 13.9% (95% CI = 12.8% to 15.1%) to 23.1% (95% CI = 21.8% to 24.4%) for muscle strengthening (≥2 days per week) activities, and from 9.5% (95% CI = 8.4% to 10.7%) to 17.9% (95% CI = 16.7% to 19.1%) for both combined (all Ptrend < .001). From 2004 to 2018, the prevalence of insufficient sleep duration (<7 hours per day) increased from 28.4% (95% CI = 26.3% to 30.5%) to 30.8% (95% CI = 29.3% to 32.2%) (Ptrend = .004). Daily sitting time increased from 6.09 hours per day (95% CI = 5.71 to 6.46 hours per day) in 2007-2008 to 7.36 hours per day (95% CI = 7.05 to 7.68 hours per day) in 2013-2014 and attenuated to 6.20 hours per day (95% CI = 5.74 to 6.65 hours per day) in 2017-2018. The pattern of physical activity, sleep, and sitting time varied by sex, race and ethnicity, body mass index, cancer type, and time since cancer diagnosis. CONCLUSIONS: More than half of US cancer survivors did not meet physical activity guidelines, and a large proportion had insufficient sleep duration and prolonged sitting time.