Abstract: The present disclosure provides isolated antibodies, particularly human antibodies, or antigen binding portions thereof, that bind to osteopontin with high affinity. Nucleic acid molecules encoding the antibodies of the disclosure, expression vectors, host cells and methods for expressing the antibodies of the disclosure are also provided. Immunoconjugates, bispecific molecules and pharmaceutical compositions comprising the antibodies or antigen binding portions thereof are also provided. The disclosure also provides methods for treating various cancers using the anti-osteopontin antibodies or antigen binding portions thereof described herein.