Background and Objective: Emerging and crucial public health issues like Anti-microbial resistance (AMR) need special attention amongst the general population, especially adolescents since it is not typically a part of the school curriculum but is essential for a healthier society. The current study aimed to determine the effectiveness of an online module-based intervention package in improving the knowledge regarding AMR among school-going adolescents. Methods: A non-randomized controlled interventional study was conducted among school-going adolescents aged 15–18 years (standard 9th–12th). In the intervention and control groups, 429 and 428 students were recruited, respectively. An online module-based intervention package comprising a booklet and interactive lectures to improve knowledge of anti-microbial resistance was implemented. A pre-tested and validated questionnaire containing ten multiple-choice questions with a single correct answer (maximum total score of 10) was used in the baseline and the follow-up survey. Generalized linear models assessed the effectiveness of the intervention considering the baseline and the follow-up observations. Results: The mean age of the intervention and control groups were 15.52 (±1.25) years and 15.51 (±1.18) years, respectively, and 72.20% and 68.53%, respectively, were females. Following the intervention, the participants in the intervention group had a statistically significant improvement in their knowledge regarding AMR. Adjusting for the effects of age, gender, and baseline knowledge, the intervention group had a relative risk (95% confidence interval) of 1.13 (1.09 – 1.18) for scoring at least 5 and 1.26 (1.24 – 1.28) for unit improvement in score in the post-intervention assessment. Conclusions: School-going adolescents are often the gateway to enlightening society with new knowledge and healthy habits. After the intervention, there was an improvement in the knowledge of the intervention group. Designing an effective school-based intervention package regarding AMR is essential. Intervention at an early age in this regard is critical to building a healthier society.