["Geriatrics &Gerontology International, Volume 26, Issue 6, June 2026. ", "\nThis study categorized social participation among older adults into six domains. Multivariable logistic regression showed that higher participation in five domains—community contribution, hobbies, leisure, support, and work—was significantly associated with a lower prevalence of loneliness, suggesting distinct links between participation types and psychological well‐being.\n\nABSTRACT\n\nAim\nLoneliness among older adults is a public health concern linked to adverse mental and physical outcomes. Social participation has been shown to influence loneliness, but few studies have empirically classified types of social participation and examined their associations with loneliness. Therefore, the present study aimed to categorize social participation among community‐dwelling older adults and clarify its association with loneliness.\n\n\nMethods\nIn this cross‐sectional study, we analyzed data from 5395 community‐dwelling older adults aged ≥ 65 years in Tokai, Japan. Social participation was assessed across 16 activity domains and classified using exploratory factor analysis. Loneliness was measured using the University of California, Los Angeles Loneliness Scale (version 3). Logistic regression analyses were conducted to examine associations between social participation and loneliness, adjusting for potential confounders.\n\n\nResults\nExploratory factor analysis, supported by parallel analysis, identified five latent factors: “community contribution activities,” “hobbies and learning activities,” “participation in local events,” “leisure and outing activities,” and “support and care.” Including “work” as a standalone domain, five empirically extracted social participation factors and one conceptually retained standalone domain (work) were ultimately analyzed. Among these, five categories—“community contribution activities” (adjusted odds ratio [OR]: 0.943, 95% CI: 0.892–0.997), “hobbies and learning activities” (OR: 0.900, 95% CI: 0.848–0.953), “leisure and outing activities” (OR: 0.764, 95% CI: 0.697–0.837), “support and care” (OR: 0.880, 95% CI: 0.800–0.970), and “work” (OR: 0.754, 95% CI: 0.650–0.874)—were significantly associated with lower odds of loneliness. In contrast, “participation in local events” showed no significant association.\n\n\nConclusions\nSocial participation among older adults can be classified into several meaningful domains, each of which exhibits a distinct association with loneliness. While these associations suggest how social participation relates to loneliness, causal inferences cannot be drawn from the present findings. Further longitudinal research must clarify the directionality and temporal nature of these relationships.\n\n"]