BackgroundAdolescent depression is a serious mental disorder that makes family problems, learning challenges, drug addiction, and increases absenteeism from school. It also has a major impact on a person’s ability to manage his or her daily tasks. In the end, the condition may result in self-destruction. Research is scarce among high schools in the study setting. Therefore, this study aimed to assess the prevalence and its associated factors of depression among high school adolescent students in Bahirdar City, Northwest Ethiopia in 2022.MethodsAn institutional-based cross-sectional study was done from June 18 to July 16, 2022, among public and private high school adolescent students in Bahir Dar City, Amhara region, Ethiopia. A two-stage sampling technique was utilized. First, stratification by school type was made and schools were selected 30–40% by using a simple random sampling technique. Finally, an updated sampling frame was taken from each school director to select a sample of 584 study participants after proportional allocation by simple random sampling from six high schools. Patient Health Questionnaires were used to assess depression in high school students. The independent variables, like substance-related factors, were assessed by yes-or-no questions, and the academic stressor by academic stress in secondary education, was assessed by structured questionnaires. Binary and multivariate logistic regressions were used to identify factors associated with depression. Statistical significance was declared at a 95% confidence interval when the value of p was less than or equal to 0.05.ResultsThe response rate of the participants was 96.9%. The overall magnitude of adolescent depression was found to be 22.1% (95%CI 18.7, 25.7%). Being female (AOR: 3.43; 95%CI 2.11, 5.56), small family size (AOR: 3.01; 95%CI 1.47, 6.15); ever alcohol use (AOR: 2.40; 95%CI 1.51, 3.81); attending a public school (AOR: 3.01; 95%CI 1.68, 5.40), and having a history of abuse (AOR: 1.92; 95%CI 2.2, 3.08) were associated with depression.ConclusionIn this study, the magnitude of depression among high school students in Bahir Dar City was higher than the national threshold. There was a significant association between sex, family size of parents, ever alcohol use, public schools, and having a history of abuse with depression among adolescents. Hence, it is better for schools to screen and provide intervention for depression in public high school students and offer therapies, especially in females and those with a history of abuse, small family size, or alcohol use.