ImportanceAcute stroke is associated with accelerated, years-long cognitive decline. Whether education levels are associated with faster cognitive decline after stroke is unclear.ObjectiveTo evaluate the association of education level with poststroke cognitive decline and to determine whether age at stroke modifies the association.Design, Setting, and ParticipantsIndividual participant data meta-analysis of 4 US cohort studies (January 1971 to December 2019). Analysis began August 2022 and was completed in January 2024.ExposuresEducation level (less than high school, completed high school, some college, and college graduate).Main Outcomes and MeasuresHarmonized cognitive outcomes were global cognition (primary outcome), memory, and executive function. Outcomes were standardized as t scores (mean [SD], 50 [10]); a 1-point difference represents a 0.1-SD difference in cognition, with higher score representing better function. Linear mixed-effect models estimated the trajectory of cognitive decline after incident stroke.ResultsThe analysis included 2019 initially dementia-free stroke survivors (1048 female [51.9%]; median [IQR] age at stroke, 74.8 [69.0-80.4] years; 339 with less than a high school education [16.7%]; 613 who completed high school [30.4%]; 484 with some college [24.0%]; 583 with a college degree or higher [28.9%]). Median (IQR) follow-up time after stroke was 4.1 (1.8-7.2) years. Compared with those with less than a high school degree, college graduates had higher initial poststroke performance in global cognition (1.09 points higher; 95% CI, 0.02 to 2.17 points higher), executive function (1.81 points higher; 95%CI, 0.38 to 3.24 points higher), and memory (0.99 points higher; 95% CI, 0.02 to 1.96 points higher). Compared with stroke survivors with less than a high school education, there was a faster decline in executive function among college graduates (−0.44 points/y faster; 95% CI, −0.69 to −0.18 points/y faster) and those with some college education(−0.30 points/y faster; 95% CI, −0.57 to −0.03 points/y faster). Education level was not associated with declines in global cognition or memory. Age did not modify the association of education with cognitive decline.Conclusions and RelevanceIn this pooled cohort study, the trajectory of cognitive decline after stroke varied by education level and cognitive domain, suggesting that stroke survivors with a higher education level may have greater cognitive reserve but steeper decline in executive function than those with a lower education level.