Coinfections with hepatitis C virus (HCV) or human immunodeficiency virus (HIV) among individuals with chronic hepatitis B (CHB) are associated with worse clinical outcomes but remain understudied due to their low prevalence and the sensitivity of associated data. This nationwide, cross-sectional study utilized claims data from the Korean Health Insurance Review and Assessment Service (2014-2021) to investigate the prevalence, comorbidities, treatment patterns, and liver-related complications among patients with HBV monoinfection, HBV/HIV, HBV/HCV, or triple coinfection. Among over 4.5 million patients with chronic hepatitis B, the prevalence of HIV and HCV coinfection ranged from 0.05 to 0.07% and 0.77 to 1.00%, respectively. Patients with HBV/HCV coinfection were older and had significantly higher rates of hypertension, diabetes, dyslipidemia, and major adverse liver outcomes, including hepatocellular carcinoma and liver transplantation, compared to other groups. HBV/HIV coinfection was more common in younger males and was associated with higher dyslipidemia. The use of HBV antivirals increased over time across all groups. These findings highlight the distinct clinical characteristics and unmet needs of coinfected populations, underscoring the importance of tailored screening and management strategies in HBV-endemic settings.