Understanding factors that influence the amount of time people with stroke spend sitting and being active is important to inform the development of targeted interventions. Objective: To explore the physicalcognitive, and psychosocial factors associated with daily sitting time and physical activity in people with stroke. Method: Secondary analysis of an observational study (n = 50, mean age 67.2 11.6 years, 33 men) of adults at least 6 months post-stroke. Activity monitor data were collected via a 7-day, continuous wear (24 hours/day) protocol. Sitting time [total, and prolonged (time in bouts of ≥ 30 minutes)] was measured with an activPAL3 activity monitor. A hip-worn Actigraph GT3X+ accelerometer was used to measure moderate-To-vigorousintensity physical activity (MVPA) time. Univariate analyses examined relationships of stroke severity (National Institutes of Health Stroke Scale), physical [walking speed, Stroke Impact Scale (SIS) physical domain score], cognitive (Montreal Cognitive Assessment), and psychosocial factors (living arrangement, SIS emotional domain score) with sitting time, prolonged sitting time, and MVPA. Results: Self-reported physical function and walking speed were negatively associated with total sitting time (r = - 0.354, P = 0.022 and r = - 0.361, P = 0.011, respectively) and prolonged sitting time (r = - 0.5, P = 0.001 and - 0.45, P = 0.001, respectively), and positively associated with MVPA (r = 0.469, P = 0.002 and 0.431, P = 0.003, respectively). Conclusions: Physical factors, such as walking ability, may influence sitting and activity time in people with stroke, yet much of the variance in daily sitting time remains unexplained. Large prospective studies are required to understand the drivers of activity and sitting time.