Stigma around hepatitis C virus (HCV) infection is an important and understudied barrier to HCV treatment and elimination. The determinants of HCV-related stigma, including the impacts of stage of HCV treatment (ie spontaneously cleared; diagnosed, untreated; previously treated, not cured; currently being treated; and treated, cured) and coinfection with human immunodeficiency virus (HIV), remain unknown. To address these gaps, we conducted a cross-sectional study among patients with a history of HCV infection (n = 270) at outpatient clinics in Philadelphia from July 2018 to May 2019. We evaluated stigma using the validated HCV Stigma Scale, adapted from the Berger HIV Stigma Scale. Associations among HCV-related stigma and hypothesized demographic, behavioural, and clinical risk factors were evaluated by multivariable linear regression. Most participants (95.5%) experienced HCV-related stigma. Mean stigma scores did not differ significantly between HCV-monoinfected and HIV/HCVcoinfected participants (P = .574). However, we observed significant interactions between HIV status and multiple determinants; therefore, we stratified analyses by HIV status. Among HIV/HCV-coinfected participants, previous HCV treatment without cure, female gender, Hispanic/Latinx ethnicity and some college education were significantly associated with higher HCV-stigma scores. An annual income of $10 000-$40 000 was associated with significantly lower stigma scores. No significant associations were observed among HCV-monoinfected participants. We found that most participants experienced stigma associated with HCV diagnosis. While stigma scores were similar between HCV-monoinfected and HIV/HCV-coinfected participants, the determinants associated with HCV stigma differed by HIV status.