The present disclosure provides isolated monoclonal antibodies, particularly human monoclonal antibodies that specifically bind to CD19 with high affinity. Nucleic acid molecules encoding such CD19 antibodies, expression vectors, host cells and methods for expressing the CD19 antibodies are also provided. Immunoconjugates, bispecific molecules and pharmaceutical compositions comprising the CD19 antibodies are also provided. Methods for detecting CD19, as well as methods for treating various B cell malignancies, including non-Hodgkin's lymphoma, are disclosed.