BackgroundThe current 2019 novel coronavirus disease (COVID-19) pandemic is a major threat to global health. It is currently uncertain whether and how liver injury affects the severity of COVID-19. Therefore, we conducted a meta-analysis to determine the association between liver injury and the severity of COVID-19.MethodsA systematic search of the PubMed, Embase, and Cochrane Library databases from inception to August 12, 2022, was performed to analyse the reported liver chemistry data for patients diagnosed with COVID-19. The pooled odds ratio (OR), weighted mean difference (WMD) and 95% confidence interval (95% CI) were assessed using a random-effects model. Furthermore, publication bias and sensitivity were analyzed.ResultsForty-six studies with 28,663 patients were included. The pooled WMDs of alanine aminotransferase (WMD = 12.87 U/L, 95% CI: 10.52–15.23, I2 = 99.2%), aspartate aminotransferase (WMD = 13.98 U/L, 95% CI: 12.13–15.83, I2 = 98.2%), gamma-glutamyl transpeptidase (WMD = 20.67 U/L, 95% CI: 14.24–27.10, I2 = 98.8%), total bilirubin (WMD = 2.98 μmol/L, 95% CI: 1.98–3.99, I2 = 99.4%), and prothrombin time (WMD = 0.84 s, 95% CI: 0.46–1.23, I2 = 99.4%) were significantly higher and that of albumin was lower (WMD = −4.52 g/L, 95% CI: −6.28 to −2.75, I2 = 99.9%) in severe cases. Moreover, the pooled OR of mortality was higher in patients with liver injury (OR = 2.72, 95% CI: 1.18–6.27, I2 = 71.6%).ConclusionsHepatocellular injury, liver metabolic, and synthetic function abnormality were observed in severe COVID-19. From a clinical perspective, liver injury has potential as a prognostic biomarker for screening severely affected patients at early disease stages.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, Identifier: CRD42022325206.