We aimed to compare the influence of cardiometabolic disorders on the incidence of severe COVID-19 vs. non-COVID pneumonia. We included all consecutive patients admitted with SARS-CoV-2-positive pneumonia between 12 March 2020 and 1 April 2020 and compared them to patients with influenza pneumonia hospitalized between December 2017 and December 2019 at the same tertiary hospital in Paris. Patients with COVID-19 were significantly younger and more frequently male. In the analysis adjusted for age and sex, patients with COVID-19 were more likely to be obese (adjOR: 2.25; 95% CI 1.24–4.09; p = 0.0076) and receive diuretics (adjOR: 2.13; 95% CI 1.12–4.03; p = 0.021) but were less likely to be smokers (adjOR: 0.40; 95% CI 0.24–0.64; p = 0.0002), have COPD (adjOR: 0.25; 95% CI 0.11–0.56; p = 0.0008), or have a previous or active cancer diagnosis (adjOR: 0.54, 95% CI 0.32–0.91; p = 0.020). The rate of ICU admission was significantly higher in patients with COVID-19 (32.4% vs. 5.2% p < 0.0001). Obesity was significantly associated with the risk of direct ICU admission in patients with COVID-19 but not in patients with influenza pneumonia. Likewise, pre-existing hypertension was significantly associated with mortality in patients with COVID-19 but not in patients with influenza pneumonia. Cardiometabolic disorders differentially influenced the risk of presenting with severe COVID-19 or influenza pneumonia.