Social media have become a new context for adolescent identity development. However, it is challenging to build a thorough understanding of how social media and identity development are related because studies refer to different facets of social media engagement and use diverse concepts related to identity. This review synthesizes research on the relationships between quantity and quality of social media use and different dimensions of identity development, including identity exploration and commitment, self-concept clarity, and identity distress. The search conducted across four databases yielded 4,467 records, of which 32 studies were included in the analysis, comprising 19,658 adolescents with a mean age of 16.43 years (