•Two frailty trajectory classes were identified.•Subjective support delays frailty progression through preventing depression.•Objective support delays frailty progression through promoting physical activity.•Support utilization delays frailty progression through promoting physical activity.•Social support should be considered in the management of frailty. To investigate whether and how social support influenced frailty progression through depressive symptoms and physical activity. Of 1235 community-dwelling older adults enrolled at baseline, 778 (63.0%) undergoing at least one yearly follow-up were included in the final analysis. Data were collected on frailty, social support, depressive symptoms, physical activity and covariates. Two frailty trajectory classes were identified and labeled as alleviated frailty and deteriorated frailty. Subjective support prevented the deterioration of frailty through decreased depressive symptoms, while objective support and support utilization prevented the deterioration of frailty through increased physical activity. The pathways through which social support ameliorates frailty vary by support types. Subjective support interventions should be included in the multifactorial interdisciplinary management of frailty to address social and psychological vulnerabilities, along with objective support and support utilization interventions addressing physical inactivity.