BACKGROUND: Women experience more poststroke physical activity limitations, but sex differences in social activity participation, an important patient-reported outcome for stroke recovery, remain uncertain. METHODS: Incident stroke survivors aged ≥65 years were identified from the US NHATS (National Health and Aging Trends Study), 2011-2022. Participants were asked to report restricted participation in the past month in 2 formal activities (religious services and clubs/classes) and 2 informal activities (visiting friends/family and going out for enjoyment) in the year of stroke onset. Logistic regression was used to assess sex differences in any participation restrictions across the 4 activities and within each activity, without and with adjustment for potential confounders, including sociodemographic, social-environmental, technological- and service environmental, psychological, health condition–related factors, and activity limitations. RESULTS: Among stroke survivors (N=469; 56.6% w