Adolescents in Nairobi slums often face significant mental health challenges due to socioeconomic pressures and limited access to healthcare. A mixed-methods approach was employed, including surveys (n=200) assessing pre-intervention knowledge levels, followed by a structured intervention programme delivered over six months, and post-intervention surveys (n=200). Data were analysed using descriptive statistics to compare pre- and post-intervention knowledge scores. Pre-intervention participants reported low awareness of mental health conditions, with only 35% recognising the importance of seeking professional help. Post-intervention, this increased to 78% The educational intervention significantly improved adolescents' understanding of mental health issues and their willingness to seek support. Future research should focus on replicating and scaling up these interventions in broader populations and exploring the long-term effects. Adolescents, Mental Health Literacy, Education Interventions, Nairobi Slums