Abstract Background Stroke survivors exhibit a higher prevalence of sleep disturbances and physical activity (PA) deficiencies. The joint effects of the two behaviors on mortality risk among stroke survivors remains unclear. This study aimed to explore the joint association of PA and sleep quality with the all-cause and cardiovascular disease ( CVD ) mortality risk in stroke survivors. Methods A total of 5,507 stroke survivors from the UK Biobank were included to assess the independent or joint associations of sleep score and PA with mortality. PA levels were categorized as meeting recommended moderate-to-vigorous physical activity (MVPA) and not meeting recommended MVPA. Sleep quality was classified as healthy, poor/intermediate based on a novel sleep score, leading to the identification of four distinct PA-sleep combinations. Cox proportional hazard models were employed to estimate hazard ratio (HR) for all-cause and cardiovascular disease (CVD) mortality, with data ascertained through October 2021. The dose-response relationship between PA or sleep duration and mortality risk were explored by plotting restricted cubic splines. Sensitivity analyses were conducted to examine the robustness of the results. Results After an average follow-up of 12.55 years, healthy sleep score group were associated with an decreased all-cause mortality risk compared to poor/intermediate sleep score group (HR: 0.873; 95% CI: 0.767–0.995). Compared to individuals who did not meet the recommended MVPA levels, those who did achieve the recommended MVPA levels was exhibited a significantly lower risk of all-cause mortality (HR, 0.729; 95% CI, 0.640–0.831) and CVD mortality (HR, 0.786; 95% CI, 0.627–0.986). PA levels exhibit an L-shaped association with mortality(cut off value = 2,000 MET-minutes per week). Participants meeting MVPA recommendations and/or reporting healthy sleep scores reduced 28.5–35.9% risk of all-cause mortality. Conclusions Poor sleep quality is associated with a elevated risk of all-cause mortality. Stroke survivors meeting recommended MVPA levels exhibit lower mortality risk, even among those with poor sleep quality. Future intervention studies are needed to establish whether increasing PA to recommended levels among stroke survivors directly reduces mortality risk linked to poor sleep quality.