Background Community-acquired pneumonia due to viral pathogens is an under-recognized cause of healthcare-associated mortality and morbidity worldwide. We aimed to compare mortality rates and outcome measures of disease severity in obese vs non-obese patients admitted with viral pneumonia. Methods Adult patients admitted with viral pneumonia were selected from the Nationwide Inpatient Sample of 2016 and 2017. The arms were stratified based on the presence of a secondary discharge diagnosis of obesity. The primary outcome was inpatient mortality. Secondary outcomes included sepsis, acute respiratory failure, acute respiratory distress syndrome, acute kidney injury, and pulmonary embolism. Results and interpretation In total, 89,650 patients admitted with viral pneumonia were analyzed, and 17% had obesity. There was no significant difference in mortality between obese and non-obese patients (aOR: 0.98, 95% CI: 0.705 - 1.362, p < 0.001). Compared to non-obese patients, obese patients had higher adjusted odds of developing acute hypoxic respiratory failure (aOR: 1.37, 95% CI: 1.255 - 1.513, p < 0.001), acute respiratory distress syndrome (aOR: 2.29, 95% CI: 1.554 - 3.381, p < 0.001), need for mechanical ventilation (aOR: 1.50, 95% CI: 1.236 - 1.819, p < 0.001), and pulmonary embolism (aOR: 1.69, 95% CI: 1.024 - 2.788, p = 0.040). Conclusions Obesity was not found to be an independent predictor of inpatient mortality in patients admitted with viral pneumonia. However, obesity is associated with worse clinical outcomes and disease severity as defined by the presence of complications, greater incidence of acute respiratory failure (ARF), acute respiratory distress syndrome (ARDS), need for mechanical ventilation, acute kidney injury (AKI), pulmonary embolism (PE), stroke, and sepsis.