We examined the relative associations of aortic and carotid artery stiffness with cerebrovascular disease (CeVD), cognition, and dementia subtypes in a memory clinic cohort of 272 participants (mean age = 75.4, SD = 6.8). We hypothesized that carotid artery stiffness would have greater effects on outcomes, given its proximate relationship to the brain. Aortic and carotid artery stiffness were assessed with applanation tonometry and carotid ultrasonography, respectively. CeVD markers included white matter hyperintensities (WMH), lacunes, cerebral microbleeds, cortical infarcts, and intracranial stenosis. Cognition was assessed by the Mini Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and a neuropsychological battery. Multivariable linear regression was conducted to determine associations of arterial stiffness with WMH and cognition, while logistic regression analysed associations with CeVD markers and dementia subtypes. Carotid artery stiffness z-score was associated with WMH, cortical infarcts, vascular cognitive impairment, and MMSE, independent of age, sex, education, vascular risk factors, and aortic stiffness z-score. Although aortic stiffness z-score was independently associated with cortical infarcts, this became non-significant after further adjusting for carotid artery stiffness z-score. We found that carotid artery stiffness had greater effects on CeVD, cognitive function and impairment in memory clinic patients compared to aortic stiffness.