Mucin 16 (MUC16) is highly expressed in ovarian cancer and expression on cancer cells is shown to protect tumor cells from the immune system. The present invention provides novel full-length human IgG antibodies that bind to human and MUC16 (monospecific antibodies). The present invention also provides novel bispecific antibodies (bsAbs) that bind to both MUC16 and CD3 and activate T cells via the CD3 complex in the presence of MUC16-expressing tumors. According to certain embodiments, the present invention provides bispecific antigen-binding molecules comprising a first antigen-binding domain that specifically binds human and monkey CD3, and a second antigen-binding molecule that specifically binds human and monkey MUC16. In certain embodiments, the bispecific antigen-binding molecules of the present invention are capable of inhibiting the growth of tumors expressing MUC16. The bispecific antigen-binding molecules of the invention are useful for the treatment of diseases and disorders in which an upregulated or induced MUC16-targeted immune response is desired and/or therapeutically beneficial. For example, the bispecific antibodies of the invention are useful for the treatment of various cancers, including ovarian cancer. The present invention also includes anti-MUC16 antibody drug conjugates which inhibit tumor growth in vivo. In some embodiments, the anti-MUC16 antibodies are useful in diagnostic methods for identifying the presence of MUC16 in tissue and/or plasma samples.