ABSTRACT Objectives The study aimed to investigate the influence mechanism underlying the relationship between Internet use and depressive symptoms in Chinese older adults. Methods Data were derived from the 2018 wave of China Longitudinal Aging Social Survey. Mediation and moderation analyses were conducted using Ordinary list squares (OLS) regression analysis. To address potential endogenous issues, we employed the Propensity Score Matching (PSM) method to explore the association between Internet use and depressive symptoms. Results Our findings indicate that Internet use can significantly reduce depressive symptoms and enhance mental health of older adults. Loneliness mediated the relationship between Internet use and depressive symptoms among older adults, while socioeconomic status (SES) moderated this relationship. Furthermore, the four purposes of Internet use, namely online chatting, information searching, recreational activities, consumption and investment, were negatively associated with loneliness and depressive symptoms among older adults. Conclusions The findings emphasize the positive effects of Internet use on the mental health outcomes of older adults. Clinical Implications The proper use of the Internet possesses considerable promise for clinical rehabilitation, targeting the enhancement of the mental health outcomes of older adults during their later life.