Background: The co-occurrence of stroke and psychosis is a serious neuropsychiatric condition, but little is known about the course of this comorbidity. Aims: To estimate longitudinal associations between stroke and psychosis over 10 years. Methods: A 10-year population-based study using data from the English Longitudinal Study of Ageing. A structured health assessment recorded i) first-occurrence stroke and ii) psychosis, at each wave. Each were considered exposures and outcomes in separate analyses. Logistic and Cox proportional hazards regression and Kaplan-Meier methods were used. Models were adjusted for demographic and health behaviour covariates, with missing covariates imputed using random forest multiple imputation. Results: Of 19,808 participants, 24 reported both stroke and psychosis (median Wave 1 age 63, 71% female, 50% lowest quintile of net financial wealth) at any point during follow-up. By 10 years, the probability of an incident first stroke in participants with psychosis was 21.4% (95% CI, 12.1 to 29.6) compared to 8.3% (95% CI, 7.8 to 8.8) in those without psychosis (absolute difference: 13.1%; 95% CI, 20.8 to 4.3, log rank p<0.001; fully-adjusted hazard ratio (HR): 3.63; 95% CI, 2.25 to 5.87). The probability of reporting incident psychosis in participants with stroke was 2.3% (95% CI, 1.4 to 3.2) compared to 0.9% (95% CI, 0.7 to 1.1) in those without (absolute difference: 1.4%; 95% CI, 0.7 to 2.1, log rank p<0.001; fully-adjusted HR: 5.81; 95% CI, 2.89 to 11.70). Conclusions: Stroke is an independent predictor of psychosis (and vice versa), after adjustment for potential confounders.