This study examines whether regular exercise moderates the relationship between hand grip strength and cognitive function in older adults. Older adults 65 and over from the third wave of the Korean Longitudinal Study of Ageing Data were analyzed. A moderated multiple regression analysis was conducted to assess the moderating effects of regular exercise on the relationship between hand grip strength and cognitive function. According to the results, regular exercise moderated the effects of hand grip strength on cognitive function, suggesting that regular exercise should be promoted for older adults to reduce unfavorable effects of a decrease in hand grip strength on cognitive function.