The present disclosure provides antibodies and antigen binding fragments thereof including, but not limited to, monoclonal antibodies that specifically bind to human programmed death ligand 2 (PD-L2). The invention further provides nucleic acids encoding the antibodies and antigen binding fragments of the invention and host cells transformed therewith. The antibodies and antigen binding proteins of the invention are useful in methods for the immunohistochemical detection of human PD-L2 expression in tissue samples.