<p>Well-being is closely linked to employment status and plays a vital role in supporting individuals with mental illnesses in the workforce. Individual Placement and Support (IPS) programs that adopt a recovery-oriented approach to employment have been widely implemented to assist this population. Prior research examining IPS programs has focused mainly on work-related correlates of well-being. However, the relationship between community participation and well-being among workers with mental illness has not been sufficiently examined. This study aimed to clarify the relationship between well-being and community participation, measured by the number of participation domains and days, among workers with mental illnesses enrolled in IPS programs. Data were collected from July to September 2024 from 168 employed&#xa0;individuals diagnosed with mental and behavioral disorders who were receiving services at 15 institutions offering IPS programs. Participants’ demographic data, well-being scores, and community participation data were analyzed using multiple regression analysis. The results showed that well-being (<i>M</i> = 44.6, <i>SD</i> = 8.9), as the dependent variable, revealed significant associations with both the number of community participation domains (<i>B</i> = 0.61, <i>p</i> = 0.011) and participation days (<i>B</i> = 0.08, <i>p</i> = 0.002). These findings suggest that broader and more frequent community participation may contribute to higher levels of well-being among workers with mental illness receiving IPS programs.</p>