Influenza A virus subtype H5 may refer to one of nine subtypes of Influenza A virus:
Influenza A virus subtype H5N1 Influenza A virus subtype H5N2 Influenza A virus subtype H5N3 Influenza A virus subtype H5N4 Influenza A virus subtype H5N5 Influenza A virus subtype H5N6 Influenza A virus subtype H5N7 Influenza A virus subtype H5N8 Influenza A virus subtype H5N9