Introduction Although stroke is an emerging cause of disability and mortality globally, associations between physical capability markers and mortality in stroke survivors are elusive. This study investigated the individual and combined associations of walking pace and grip strength with all-cause and stroke mortality in stroke survivors. Methods Individual and combined associations of walking pace and grip strength with stroke deaths and all-cause mortality were investigated using Cox proportional-hazard models adjusted for sociodemographic, lifestyle, and health-related variables. Results Seven thousand four hundred eighty-six stroke survivors from the UK Biobank study (aged 40–70 years; 42.4% women) were included in this prospective study. Over a median follow-up of 12.6 (IQR: 11.9–13.3) years, 1490 (19.9%) participants died, of whom 222 (3.0%) died from stroke. After adjusting for confounding factors, and compared to individuals in the average/brisk walking pace category, those who reported a slow walking pace had 2.00 (95% CI: 1.50–2.68) and 1.99 (95% CI: 1.78–2.23) times higher risk of stroke mortality and all-cause mortality, respectively. Similar associations were identified for participants with low grip strength compared with those with normal levels. For combined associations, those with both slow walking pace and low grip strength showed the highest risk of stroke mortality (hazard ratio: 2.86 [95% CI: 1.93–4.22]). Similar results were found for all-cause mortality. Conclusions Low grip strength and slow walking pace were associated with a higher risk of stroke and all-cause mortality in stroke survivors. If these associations are causal, improving physical capability among stroke survivors might potentially prolong survival.