The purpose of this study is to determine the characteristics of adolescents' peer relationships, the factors affecting their social-psychological development, and to reveal the role these relationships play in shaping the individual's personality.The survey technique was used as the data collection method during the research process. Both school-age adolescents and adolescents in vocational training participated in the study. As a method, a questionnaire consisting of 11 questions prepared by the researcher was applied. The questionnaire included questions about adolescents' peer relationships and the effects of these relationships on their social-psychological development and personality formation.According to the results obtained, it was determined that strong and positive relationships established with peers significantly contribute to adolescents' personality development and the development of their empathy and communication skills. On the other hand, it was observed that conflicts in relationships and social isolation can lead to psychological tension and decreased self-esteem. The findings of the study emphasize that adolescents' development in a healthy social environment has a direct impact on their future quality of life.