Peer death is not uncommon during adolescence. Unlike the loss of family members, grief following the peer loss is often unrecognized and unsupported by society, making it difficult for adolescents to handle their grief. This may result in prolonged and intense reactions, negatively affecting academic performance and physical and mental health. In this article, we review the manifestations of, associated factors with, and interventions for grief after peer loss and discuss unaddressed questions. A literature search was conducted within three electronic databases (Web of Science, PubMed, and ScienceDirect) from January 1, 2014 to December 29, 2024. Finally, 13 English studies focusing on peer loss and grief among adolescents were identified and included. Grief over the death of a friend in adolescents could be intense, lasting up to 8.5 years, with symptoms such as post-traumatic stress disorder and sleep disturbances. The prolonged grief could impair mental health and social functioning. Girls tend to exhibit more complicated grief reactions and experience a longer duration of grief compared to boys. Personality traits also play a critical role: adolescents with high agreeableness tend to recover more quickly, while those with high neuroticism are less resilient. The quality of the friendship with the deceased and exposure to negative information also influence the grief intensity. Raising professional awareness, providing targeted interventions, and establishing effective social support are essential for grief recovery. Significant gaps still remain in understanding adolescent grief following peer loss, particularly in the mechanisms between different factors and grief, and the feasibility and effectiveness of specific treatment plans. Addressing these limitations is essential for advancing theoretical frameworks and developing targeted interventions. This review provides a foundational basis for future research and clinical practices, with the potential to inform therapeutic approaches and interventions that better support the healing and recovery processes of grieving adolescents.