ImportanceThe association between psychological resilience (PR) and frailty progression in older adults is not fully understood.ObjectiveTo investigate the longitudinal associations between PR and its changes (ΔPR) with frailty progression among older adults.Design, Setting, and ParticipantsData were collected from a community-based prospective cohort study conducted in Shanghai from 2020 to 2023. Older adults aged 60 years and above were recruited at baseline and completed follow-up assessments. Statistical analysis was performed from May to July 2024.ExposuresPR was assessed using the 25-item Connor-Davidson resilience scale (CD-RISC). ΔPR was calculated using the difference between 3-year follow-up and baseline CD-RISC scores. Multiple key covariates were included such as demographics, health behaviors, social participation, and chronic diseases.Main Outcomes and MeasuresFrailty was evaluated using the Chinese Frailty Screening Scale-10. Frailty progression was categorized into 3 groups (improvement, stability, and deterioration) by the difference assessment between 3-year follow-up and baseline.ResultsA total of 4033 participants were included in the study (mean [SD] age, 71.0 [6.1] years; 2257 [56.0%] women). Over a 3-year follow-up period, 1142 participants (28.3%) experienced an improvement in frailty, 1200 (29.8%) experienced stability, and 1691 (41.9%) exhibited deterioration. After controlling for confounding variables, a significant association was found between PR and future frailty, particularly when baseline frailty scores were at least 3 vs 2 or lower (β, −0.136 [95% CI, −0.214 to −0.057] vs −0.020 [-95% CI, −0.052 to 0.012]; P for interaction < .001). A similar association was observed between PR and frailty improvement (adjusted odds ratio [OR], 1.28 [95% CI, 1.05 to 1.57]). Furthermore, ΔPR displayed a significant association with frailty, exhibiting a nonlinear association that was stronger when ΔPR was less than 0 vs when ΔPR was greater than 0 (β,−0.186 [95% CI, −0.228 to −0.145] vs −0.068 [95% CI, −0.107 to −0.029]; P for nonlinear < .001). Similarly, ΔPR was significantly associated with frailty progression, indicating both improvement (adjusted OR, 1.30 [95% CI, 1.19 to 1.42]) and deterioration (adjusted OR, 0.74 [95% CI, 0.69 to 0.80]). These associations were more pronounced among older adults with higher levels of baseline frailty.Conclusions and relevanceIn this cohort study of community-dwelling older adults, a longitudinal association between PR and frailty progression was found. The results suggest that monitoring changes in PR can help forecast future frailty trajectories, particularly highlighting the need to support individuals facing declines in resilience. Targeted interventions that prioritize enhancing PR have potential to prevent and ameliorate frailty.