The present invention provides isolated monoclonal antibodies, particularly human monoclonal antibodies, that specifically bind to PTK7 with high affinity. Nucleic acid molecules encoding the antibodies of the invention, expression vectors, host cells and methods for expressing the antibodies of the invention are also provided. Immunoconjugates, bispecific molecules and pharmaceutical compositions comprising the antibodies of the invention are also provided. The invention also provides methods for detecting PTK7, as well as methods for treating various diseases, including cancer and infectious diseases, using anti-PTK7 antibodies.text