The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet is a brain-focused dietary pattern designed to prevent cognitive decline in older adults. This systematic review, conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, aimed to examine the association between the MIND diet and cognitive function in older adults. Relevant studies published between 2015 and 2024 were identified through comprehensive searches of PubMed and the Cochrane Library using keywords including “MIND diet,” “cognitive performance,” and “older adults.” From a total of 138 records screened, 11 studies met the inclusion criteria after excluding reviews, meta-analyses, editorials, and those incorporating other lifestyle interventions such as physical activity or education. These studies included 7 prospective cohort studies, 2 cross-sectional studies, 1 randomized controlled trial (RCT), and 1 case-control study, comprising a total of 17,201 participants aged 57–91 years. Across studies, at least 57% of participants were women, and in the 5 studies reporting race, more than 75% were White. Dietary intake and MIND adherence were assessed primarily via food frequency questionnaires, while cognitive outcomes were evaluated using validated instruments including the Montreal Cognitive Assessment, global cognition scores, Consortium to Establish a Registry for Alzheimer’s Disease tests, and magnetic resonance imaging. Six cohort and two cross-sectional studies reported significant associations between higher MIND adherence and better cognitive outcomes. One cohort study and the single RCT showed no effect. Excluding 2 studies with short durations (≤ 3 years), the remaining nine studies suggest consistent cognitive benefits of MIND adherence. Future studies should include systematic reviews and large-scale RCTs focusing on Asian populations.