Medication nonadherence among patients with chronic hepatitis B (CHB) can lead to severe liver disease progression, including liver cirrhosis and hepatocellular carcinoma (HCC). Yet the factors that influence adherence in high-risk groups, like Korean Americans, remain unclear. Thus, this study explored the psychosocial and clinical factors affecting medication adherence in CHB patients. A cohort of 365 Korean American patients with CHB from two clinics in Philadelphia and Los Angeles was studied. The 8-item Morisky Medication Adherence Scale (MMAS-8) gauged their adherence to antiviral medication. Using descriptive and multivariable logistic regression analyses, we identified factors associated with MMAS-8 scores. Of the participants, 78% were undergoing antiviral therapy, with over two-thirds (69%) reporting medium to high adherence levels. The multivariable logistic regression analysis revealed that age, knowledge of sequalae of CHB, perceived HBV stigma and possession of pharmacy plan were associated with medication adherence. Older participants had higher medication adherence than younger. High knowledge of sequalae of CHB and low perceived HBV stigma were associated with higher medication adherence. Having pharmacy plans was also associated with higher medication adherence to antiviral therapy. These findings highlight the critical role of person-related factors (e.g., knowledge and stigma) and healthcare factors in medication adherence. Future research should focus on developing targeted educational interventions focusing on personal factors to improve medication adherence among Korean American patients with CHB.