Introduction: This study aimed to assess the knowledge, attitudes, and practices related to coronavirus disease 2019 (COVID-19) among adolescents in India, recognizing the vital role this demographic plays in pandemic control. Materials and Methods: Conducted at the Medical College, Kolkata COVID-19 vaccination center from June to August 2022, this web-based prospective cross-sectional study included individuals aged 13–19 years. Data collection involved a structured questionnaire in multiple languages, ensuring broad accessibility. Ethical standards were upheld with online informed consent and rigorous data confidentiality measures. Results: The study revealed balanced gender representation among participants, with most enrolled in the 10th or 12th standard. Parents’ educational backgrounds varied, but a significant proportion had family members employed in the health-care sector (66.7%). Knowledge about COVID-19 in India was surprisingly limited: only 3.7% knew about oxygen saturation and its utility. 18.75% considered depression as a comorbidity of COVID-19. 73.8% of the participants relied on social media for information about COVID-19. A majority (66.25%) of the participants believed 2 doses of the vaccine would protect them from the disease. Twice as many women believed in the protection offered by vaccines. Conclusion: This research, distinct from conventional scoring-based studies, emphasized uncovering misconceptions and knowledge gaps. Importantly, many adolescents lacked awareness of the true COVID-19 situation in India, potentially undermining the pandemic gravity perception and preventive measures. Although participants showed awareness of common COVID-19 symptoms and preventive measures, knowledge about comorbidities’ influence on mortality rates was limited.