Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that predominantly affects the axial skeleton, although it can affect peripheral joints, and extra-musculoskeletal manifestations also occur. Historically, axSpA was thought to be a disease predominantly seen in men, although with the advent of magnetic resonance imaging techniques and advances in research, this dogma has been challenged and refuted. Sex and gender are different concepts, and both can have a role in disease. In axSpA, consideration of the influence of sex and gender on the disease phenotype is necessary to predict outcomes and to enable the development of therapeutic approaches that are best suited to individual patients.