The present disclosure provides isolated monoclonal antibodies or an antigen-binding portion thereof that specifically bind to CD40 preferably human CD40 with high affinity, and that function as CD40 agonists. The disclosed invention also relates to antibodies that are chimeric, humanized, bispecific, derivatized, single chain antibodies or portions of fusion proteins. Nucleic acid molecules encoding the antibodies of the disclosed invention, hybridoma, and methods for expressing the antibodies of the disclosed invention are also provided. Pharmaceutical compositions comprising the antibodies of the disclosed invention are also provided. This disclosure also provides methods for regulating humoral and cellular immune responses, as well as methods for treating cancer using an anti-CD40 agonist antibody of the disclosed invention.