A novel calicivirus (strain H146) was detected in a goose and sequenced. The H146 genome consisted of two open reading frames (ORFs) with an 8-nucleotide (nt) overlap between the two ORFs, similar to what has been found in the bat sapovirus TLC58. The virus was most closely related to nacoviruses when comparing the complete genome sequence (49% identity), non-structural region (NS; 31-34% amino acid [aa] sequence identity), and major structural VP1 region (28-30% aa identity), whereas both goose calicivirus N and feline calicivirus were the closest relatives of H146 in the VP2 region (20% aa sequence identity). The levels of divergence between H146 and its closest relatives in different genomic regions are comparable to those between some members of different genera. Phylogenetic analysis based on the NS and VP1 amino acid sequences clearly demonstrated that H146 formed a separate clade. Thus, calicivirus H146 was identified as a founding member of a novel genus for which we propose the name "Sanovirus".