The present invention provides antibodies that specifically bind to CD123. The invention further relates to immunoconjugates (e.g., antibody-drug conjugates, or ADCs) comprising such antibodies, antibody encoding nucleic acids, and methods of obtaining such antibodies. The invention further relates to therapeutic methods for use of these antibodies and ADCs for the treatment of a condition associated with cells expressing CD123 (e.g., cancer or autoimmune disease).