Substance abuse among adolescents continues to be a significant global concern, with profound implications for both youth development and national well-being. Of particular concern is the widespread prevalence of substance abuse during adolescence, a critical developmental stage. This study investigates the factors influencing substance abuse among adolescents in a selected community within the Badagry Local Government Area of Lagos State. The objectives include assessing adolescents’ knowledge of substance abuse, identifying factors contributing to their engagement, and determining the most commonly abused substances. Employing a descriptive research design, the study sampled 100 adolescents using multistage and convenience sampling techniques. Data were collected through a self-designed, pre-tested questionnaire and analyzed using SPSS (version 27), with results presented in tabular form. Findings indicate that while all respondents were aware of substance abuse and its detrimental effects, key influences driving abuse include peer pressure, easy access, curiosity, poverty, pursuit of pleasure, and exposure to substance abusers in their environment. The substances most frequently abused among the adolescents are alcohol (86%), cannabis (60%), coffee (84%), cough syrup (73%), and tramadol (72%). The study concludes that despite high awareness, engagement in substance use remains prevalent, prompting recommendations for enhanced parental supervision regarding peers, governmental restrictions on the importation of harmful substances, and stricter regulatory oversight to limit availability within communities