Background: Adolescence is an important stage of building psychological and social skills necessary for mental health. However, these could be altered by factors such as peer pressure, cruel parenting, media, stress, low socioeconomic status, and adverse-environmental exposure. In adolescents, mental disorder contributes to a 13% global disease burden- with depression, and anxiety problems recognised as the leading disorder among the ages 15-19. Similarly, suicide is among the top five leading causes of death in this age group of 15-19 years. While most adolescents’ mental health disorder risk factors have been extensively investigated, the association between sexual activities in adolescents and their mental health or mental disorder requires further attention. Furthermore, few primary studies like cross-sectional, case-control, longitudinal/cohort, correlation, and comparative studies have been conducted to find out the association between sexual activities in adolescents and their mental health. Still, no research has been conducted to synthesise these studies into a single document to better inform policy decisions on promoting mental wellness in young people. Aims and Objectives: The aim of this study is to evaluate the impact of early sexual activities in young people aged 10-17 years on their mental health and to use pooled estimates to establish precision of Results. The study seeks to synthesize all available primary studies into a single study. Methods: PsycINFO, Web of Science, CINAHL, Cochrane and PubMed electronic databases were searched for available literature that will answer the study’s research question.  Results: Out of 32 studies selected for full screening, only 9 met the inclusion criteria for the study. These 9 studies make up the included studies for the review. Conclusions: Seven of the nine studies showed statistically significant association between early sexual activities in adolescents’ and their mental health outcome of interest, with more consequence on the girls when compared to the boys.