Background and objectives <p>With the issue of global aging, interpersonal relationships among older adults are diminishing in both scope and quality, rendering them more vulnerable to social neglect and exclusion. This phenomenon leads to an increase in feelings of loneliness among the older population and a decrease in prosocial behavior, which significantly impacts their psychological well-being and overall quality of life. Therefore, it is imperative for governments and society to prioritize this issue. Our study aims to investigate the impact of older adults’ engagement in physical activities on their prosocial behavior, with a specific focus on examining the mediating role of “social empathy”.</p> Methods <p>A random cross-sectional survey was conducted among 466 older adults who engaged in exercise. These participants completed questionnaires assessing their levels of Physical Exercise Participation, Prosocial Behavior, and Interpersonal Response Indicators. The data were processed and analyzed using IBM SPSS Statistics software (version 26.0).</p> Results <p>The mediating effect of empathy on the relationship between older adults’ participation in physical activities and their pro-social behavior was found to be statistically significant (Z = 3.74, <i>p</i> &lt; 0.001). Specifically, cognitive empathy significantly mediated this relationship (Z = 4.71, <i>p</i> &lt; 0.001), as did emotional empathy (Z = 3.23, <i>p</i> &lt; 0.001).</p> Conclusion <p>The study revealed that engaging in physical activities can significantly promote prosocial behavior among older Chinese adults. Additionally, participation in such activities enhances social empathy levels among older adults. The research underscores the pivotal role of social empathy in fostering prosocial behavior. It was observed that older adults who engaged in physical activities demonstrated higher levels of prosocial behavior. Additionally, empathy was found to amplify the positive impact of physical activity on prosocial behavior.</p>