Duck hepatitis B virus, abbreviated DHBV, is part of the genus Avihepadnavirus of the Hepadnaviridae, and is the causal agent of duck hepatitis B. DHBV is a small DNA virus with a diameter of 40–45 nm.

The icosahedral nucleocapsid within, is composed of the virus core antigen (DHBcAg) and surrounds the DNA genome and viral polymerase.

The viral genome is a circular double stranded DNA molecule about 3000 base pairs long.

Novel viral RNA is then transferred to the cytoplasm for translation and subsequent protein synthesis.

[1] The virus has also provided as a useful animal model in the absence of one from the HBV,[2] and as scaffold for the development of chimeric virus-like particles.