School-based mental health care programmes have been implemented to address the growing need for support among urban youth in Kenya aged 15-20 years. A comprehensive search was conducted using electronic databases, including PubMed, Embase, and Web of Science. Studies were selected based on predefined inclusion criteria focusing on the effectiveness of school-based mental health care programmes in urban youth aged 15-20 years in Kenya over a four-year period. Findings indicate that student engagement improved by an average of 18% (95% CI: [14%, 22%]) and academic performance saw a notable increase, with students scoring on average 7.6 points higher (p < 0.001) in standardised test scores. The review suggests that school-based mental health care programmes can significantly enhance both student engagement and academic outcomes among urban youth aged 15-20 years in Kenya. Further research should explore long-term impacts and evaluate the sustainability of these programmes, with a focus on replication studies to confirm initial findings. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.