Background: Adolescents are more prone to depression, which needs early identification. Aim: The aim of the study is to assess the prevalence of depression in school-going adolescents and its association with their scholastic performance. Materials and methods: This questionnaire-based cross-sectional study was conducted on 473 students, among whom 271 girls and 202 boys with an age group of 12-17 years, who were selected through simple random sampling from four high schools located in and around Kolar city, Karnataka, India, from January 2023 to March 2023, were included in the study after obtaining three informed consents from adolescents. A questionnaire was given to all the study participants, and the depression was assessed according to the Centre for Epidemiological Studies Depression Scale for Children (CES-DC) score. The severity of depression among the children was assessed by the Patient Health Questionnaire-A (PHQ-A). Further, these children were assessed for their scholastic performance based on their final examination scores. The data were entered into an Excel sheet, and statistical analysis was performed. Results: A total of 473 subjects were included in the present study; 177 had depression, which represents 37% of the total population. According to PHQ-A, 31% had mild depression, 5% had moderate depression, and 1% had severe depression. The association between depression and scholastic performance was not significant. Conclusion: In the current study sample, depression was found to be mild to moderate, which reflects the overall performance of adolescents. All students were treated accordingly. Hence, active measures are to be initiated to prevent depression.