Monoclonal antibodies are provided that selectively bind human hepcidin-25 and are characterized as having high affinity for human hepcidin-25 and strong human mature hepcidin neutralizing properties. The antibodies of the invention are useful therapeutically for increasing serum iron levels, reticulocyte count, red blood cell count, hemoglobin, and/or hematocrit in a human and for the treatment and diagnosis of mature hepcidin-promoted disorders such as anemia, in a human subject.