Objectives To compare the cognitive profile of a population representative sample with orthostatic hypotension (OH) with the profile of a sample without. Design Cross-sectional analysis of a prospective nationally representative population study. Setting The Irish Longitudinal Study on Ageing (TILDA). Participants TILDA participants (N = 5,936; mean age 63 ± 9, 54% female). Measurements OH was defined as a drop of 20 mmHg or more in systolic blood pressure or of 10 mmHg or more in diastolic blood pressure on standing from a seated position. Cognitive performance was assessed using comprehensive cognitive tests measuring domains of global function, executive function, processing speed, attention, and memory, from which composite standardized scores were computed. Multivariate analysis controlling for potential confounders was performed to compare cognitive performance according to OH status. Results Prevalence of OH was 6.1% (95% confidence interval = 5.4-6.7%). A significant negative association between OH status and global cognitive function (β = -0.21, P =.01) and memory (β = -0.26, P =.002) was found in women aged 65 and older after adjustment for demographic characteristics, mental health, cardiovascular disease, and medications (antihypertensive and antipsychotic), but other specific cognitive domains were not affected. Conclusion OH was associated with poorer global cognitive function and poorer memory, independent of potential confounders, in women in a large population-based sample of older adults. Longitudinal studies with concomitant assessment of cerebral perfusion are needed to determine causal relationships.