Objectives: Benefit finding, which refers to perceiving positive life changes resulting from adversity, has been associated with better psychosocial well-being in different chronic illnesses. However, little research to date has examined how benefit finding develops in the context of Type 1 diabetes (T1D). The present study aimed to identify trajectories of benefit finding across adolescence and to investigate prospective associations with depressive symptoms, self-care, and metabolic control. Method: Adolescents with T1D aged 10 to 14 (Mage = 12.49 years, 54% girls) participated in a 4-wave longitudinal study spanning 1.5 years (N = 252 at Time 1). Adolescents filled out questionnaires on benefit finding, self-care, depressive symptoms, and illness perceptions. HbA1c values were obtained through point of care assays. We used latent growth curve modeling (LGCM) and latent class growth analysis (LCGA) to examine the development of benefit finding. Cross-lagged path analysis and multi-group LGCM were used to examine prospective associations among the study variables. Results: Adolescents reported moderate levels of benefit finding which decreased over time. Three benefit finding trajectory classes were identified: low and decreasing, moderate and decreasing, and high and stable. These trajectory classes differed in terms of self-care, perceived personal and treatment control, and perceptions of illness cyclicality. Higher levels of benefit finding predicted relative increases in self-care 6 months later. Benefit finding was not prospectively related to depressive symptoms and metabolic control. Conclusions: Benefit finding may serve as a protective factor for adolescents with Type 1 diabetes and may motivate these adolescents to more closely follow their treatment regimen.