The COVID-19 pandemic, caused by the SARS-CoV-2 virus, is associated with significant morbidity and mortality due to pneumonia, acute respiratory distress syndrome (ARDS) and multiorgan failure. Liver injury has been reported as a non-pulmonary manifestation of COVID-19 but characterization of liver test abnormalities and their association with clinical outcomes is incomplete. We conducted a retrospective cohort study of 1827 patients with confirmed COVID-19 who were hospitalized within the Yale-New Haven Health System (YNHHS) between March 14, 2020 and April 23, 2020. Clinical characteristics, liver tests (AST, ALT, ALP, TBIL, albumin) at three time points (pre-infection baseline, admission, peak hospitalization), and hospitalization outcomes (severe COVID-19, ICU admission, mechanical ventilation, death) were analyzed. Abnormal liver tests were commonly observed in hospitalized patients with COVID-19, both at admission (AST 66.9%, ALT 41.6%, ALP 13.5%, TBIL 4.3%) and peak hospitalization (AST 83.4%, ALT 61.6%, ALP 22.7%, TBIL 16.1%). Most patients with abnormal liver tests at admission had minimal elevations 1-2x ULN (AST 63.7%, ALT 63.5%, ALP 80.0%, TBIL 75.7%). A significant proportion of these patients had abnormal liver tests pre-hospitalization (AST 25.9%, ALT 38.0%, ALP 56.8%, TBIL 44.4%). Multivariate analysis revealed an association between abnormal liver tests and severe COVID-19, including ICU admission, mechanical ventilation, and death; associations with age, male gender, BMI, and diabetes mellitus were also observed. Medications used in COVID-19 treatment (lopinavir/ritonavir, hydroxychloroquine, remdesivir, and tocilizumab) were associated with peak hospitalization liver transaminase elevations >5x ULN. Conclusion: Abnormal liver tests occur in most hospitalized patients with COVID-19 and may be associated with poorer clinical outcomes.