The present invention provides an antibody that binds to the p19 subunit of human IL-23 and is characterized as having high affinity, selective, and neutralizing properties. The antibody is useful in the treatment or prevention of an autoimmune or inflammatory condition selected from the group consisting of consisting of multiple sclerosis, rheumatoid arthritis, psoriasis, inflammatory bowel diseases, ankylosing spondylitis, graft-versus-host disease, lupus and metabolic syndrome. The antibody is also useful in the treatment of cancer.