China has a high prevalence of HBV. Despite previous studies, uncertainty remains about the association of HBV with depression. This study explores the strength of the association and the modifying effects of participants' self-awareness of the disease and their socio-economic status. Data from the baseline of a Chinese cohort study of approximately 500 000 adults were analysed. Depression was assessed using the Composite International Diagnostic Inventory. Blood spot tests were conducted to detect hepatitis B surface antigen. Logistic regression was used to assess the association between depression and HBV adjusting for demographic, socio-economic and lifestyle factors of major depression. To understand the effect modifications of disease self-awareness and socio-economic factors, a series of stratified analyses were undertaken. The overall prevalence of HBV is 3.2%, with 2.8% screen-detected and 0.3% self-reported cases. There was an 84% increased odds of depression among self-reported HBV patients (OR=1.84, 95% CI: 1.16-2.90), but no association was found in the screen-detected group (OR=0.98, 95% CI: 0.79-1.23). Male (OR=2.28, 95% CI: 1.30-3.98), younger age (OR=3.57, 95% CI: 1.82-7.00), rural resident (OR=2.31, 95% CI: 1.36-3.94), lower household income (OR=2.38, 95% CI: 1.34-4.25) and agricultural worker (OR=2.92, 95% CI: 1.63-5.77) were found having greater odds of depression in the HBV self-aware group, compared to those without HBV. A strong association between hepatitis B self-awareness and depression was found. Lower socio-economic status could modify the association between hepatitis B status and depression. Further studies are needed to understand the underlying psychosocial mechanisms of the association.