The carcass of a peregrine falcon found at a construction site on Hung Yuen Road, Yuen Long, on April 9 has tested positive for H5N6.
The Agriculture, Fisheries & Conservation Department said it is the first case of H5N6 found in a wild bird in Hong Kong.
It said it will closely monitor the situation and continue inspecting poultry farms to ensure proper precautions against avian influenza have been implemented.
It reminded people to avoid personal contact with wild birds or live poultry and to clean their hands thoroughly after touching them.