Importance: Reducing poststroke sedentary behavior is important for reducing recurrent stroke risk, yet interventions to achieve this are scant. Objective: To assess the feasibility of, and estimate change in sedentary behavior over time associated with, a behavioral intervention. Design: Single-arm delayed baseline with postintervention and 8-wk follow-up assessment. Setting: Community based. Participants: Ambulatory, community-dwelling people with chronic stroke and reported ≥6 hr daily sitting time (N = 21). Intervention: Activating Behavior for Lasting Engagement (ABLE) was delivered by an occupational therapist 3×/wk for 4 wk. ABLE involves activity monitoring, activity scheduling, self-assessment, and collaborative problem solving. Outcomes and Measures: Feasibility (participant safety, adherence, satisfaction, and reliable intervention delivery) was assessed against preestablished benchmarks. Changes over time in sedentary behavior (assessed with an ActivPAL micro3 device) and participation (Stroke Impact Scale–Participation subscale) were described. Results: ABLE was safe (0 serious adverse events), adhered to (11.95 sessions/participant), and reliably delivered (90.00%–97.50% adherence). Participant satisfaction was unmet (Client Satisfaction Questionnaire–8, M = 28.75, SD = 3.84). ABLE was associated with a mean group reduction in prolonged sitting of 54.95 min (SD = 81.10) at postintervention and 14.08 (SD = 58.95) at follow-up. ABLE was associated with a negligible mean group increase over time in participation at postintervention (M = 1.48%, SD = 8.52) and follow-up (M = 1.33%, SD = 15.38). Conclusions and Relevance: The ABLE intervention is feasible and may be associated with within-group reduction in sedentary behavior over time. Further refinement is indicated. What This Article Adds: The ABLE intervention uses engagement in meaningful daily activities to reduce sedentary behavior after stroke. These findings suggest that ABLE can be delivered safely and consistently. Further research is required to enhance participant satisfaction and determine the effects of ABLE on stroke survivors’ sedentary behavior.