Internalizing symptoms are becoming increasingly prevalent among adolescent within school settings as a result of social and academic pressures. These result in psychopathology and maladjustments such as anxiety, depression and other psychosomatic conditions. Concerned with the above, this study, investigated psychological sense of school membership and gender as predictors of internalizing symptoms among in-school adolescents in Ibadan. Using a cross-sectional research design, multistage sampling technique was used to select 513 students from public and private secondary schools in Ibadan. Data was collected through the use of structured questionnaires. Findings showed that adolescents’ gender and psychological sense of school membership showed a joint predictive influence on internalizing symptoms (R= .525, R2=.276, F 97.12, P<0.01). There was an independent influence of gender on internalizing symptoms (t (511)=8.069 P<0.01). Adolescents’ psychological sense of school membership also had a significant independent influence on internalizing symptoms (t (511) = 8.867, P<0.01). This study revealed that psychological sense of school membership of adolescents and gender are essential in addressing internalizing symptoms amongst adolescents. Therefore, female adolescent students should be trained on emotional resilience early, psycho-educative training should be offered to teachers and other adults in the school environment and schools should intentionally create a climate that supports high psychological sense of school membership of adolescents. Psychoeducation and the implementation of interventions to prevent and address internalizing symptoms should be a part of the strategies to improve adolescents’ well-being.