Isolated VHH monoclonal antibodies are disclosed that specifically bind to a Norovirus polypeptide. In some embodiments, the Norovirus is a Genogroup I Norovirus or a Genogroup II Norovirus. In other embodiments, the Norovirus is Norwalk or MD2004 virus. In some embodiments, the monoclonal antibodies specifically bind VP1. Also disclosed are compositions including the disclosed antibodies, nucleic acids encoding these antibodies, expression vectors including the nucleic acids, and isolated host cells that express the nucleic acids. The antibodies and compositions disclosed herein can be used for detecting the presence of a Norovirus in a biological sample, or detecting a Norovirus infection. Also disclosed are methods of treating and/or preventing a NoV infection.