High levels of air pollution in megacities like Delhi pose serious health risks. This study examines the excess deaths happening due to fine particulate matter in Delhi during 2021 using the Global Exposure Mortality Model (GEMM). The analysis focused on five specific diseases: chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD), lung cancer (LNC), lower respiratory infections (LRI), and stroke (STR), as well as all non-accidental deaths caused by noncommunicable diseases (NCD) and LRI. The results showed 21,230 premature deaths (95% CI: 16,844–26,217) for GEMM-5 COD and 29,515 (95% CI: 25,714–33,323) for GEMM-NCD + LRI attributable to PM2.5. Furthermore, adherence to National Ambient Air Quality Standards (NAAQS) and World Health Organization (WHO) guidelines could prevent thousands of deaths annually. The findings of the current study highlight the critical requirement for efficient management of air pollution control measures in megacities like Delhi to protect human health.