Abstract: The present disclosure is directed to monoclonal antibodies, or antigen-binding fragments thereof, that bind to coronavirus spike proteins, including the spike protein of SARS-CoV-2. These antibodies demonstrate high affinity binding to epitopes on the coronavirus spike protein and/or broad cross-reactivity to the spike protein of various coronaviruses. Compositions comprising the anti-coronavirus antibodies, nucleic acids encoding for the antibodies, recombinant expression vectors, and host cells are also disclosed. The present disclosure is also directed to methods of diagnosing, preventing or treating coronavirus infections, including infections or disease caused by SARS-CoV-2.