BackgroundFunctional social support (FSS) impacts memory function through biological and psychological pathways. In a national sample of middle-aged and older adults in Canada, we explored the association between FSS and changes in memory over three years and investigated effect modification by age group and sex. MethodsWe analyzed data from the Comprehensive Cohort of the Canadian Longitudinal Study on Aging (CLSA). FSS was measured with the Medical Outcomes Study – Social Support Survey; memory was measured with combined z-scores from immediate and delayed recall administrations of a modified version of the Rey Auditory Verbal Learning Test. We regressed memory change scores over three years on baseline overall FSS and four FSS subtypes in separate multiple linear regression models, controlling for sociodemographic, health, and lifestyle covariates. We also stratified our models by age group and sex. ResultWe found positive associations between higher FSS and improvement in memory score, although only the tangible FSS subtype (availability of practical assistance) was significantly associated with changes in memory (β^ = 0.07; 95% confidence interval = 0.01, 0.14). After stratification by age group and sex, this association remained significant for males, although we found no evidence of effect modification. ConclusionIn a cognitively healthy sample of middle-aged and older adults, we found a statistically significant and positive association between tangible FSS and memory change over three years of follow-up. We did not find adults with low FSS to be at increased risk of memory decline compared to adults with higher FSS.