Objective: To characterize bacterial infections and antibiotic utilization in hospitalized cancer patients with coronavirus disease 2019 (COVID-19) Design: Retrospective cohort study Setting: Tertiary cancer center in New York City Patients: Hospitalized cancer patients >18 years with COVID-19 between March 1, 2020 and May 31, 2020 Methods: Patients were classified with mild (room air), moderate (nasal cannula oxygen), or severe (high-flow oxygen or mechanical ventilation) COVID-19. The primary outcome was bacterial infection rate within 30 days of COVID-19. Secondary outcomes included the proportion of patients receiving antibiotics and antibiotic length of therapy (LOT). Results: Of 358 study patients, 133, 97, and 128 had mild, moderate, and severe COVID-19, respectively. Most patients had a solid tumor (234/358, 65%). Two hundred (56%) patients had 245 bacterial infections of which 67 (27%) were microbiologically confirmed. The proportion of patients with bacterial infection increased with COVID-19 severity (mild: 47 (35%) vs moderate: 49 (51%) vs severe: 104 (81%), P<0.0001). Most (274/358, 77%) received antibiotics for a median of 4 days. The median antibiotic LOT was 7 days with 1 infection and 20 days for multiple infections (P<0.0001). Antibiotic duration was 1, 4, and 8 days (P<0.0001) in patients with mild, moderate, and severe COVID-19, respectively. Conclusions: Hospitalized cancer patients with COVID-19 had a high rate of bacterial infections. As COVID-19 severity increased, the proportion of patients diagnosed with bacterial infection and given antibiotics rose. In mild COVID-19 cases, antibiotic LOT was short, suggesting that empiric antibiotics can be safely avoided or discontinued in this group.