Animal models of human diseases include experimental animals and related materials established during biomedical research, which in turn play a vital role in medical research. Pigs and humans are similar in terms of their anatomy, physiology, immunology, and genetics. Pigs are thus suitable model animals for biomedical research and have various advantages compared with other model animals. Recent advances in biotechnology, such as genetic engineering, have contributed to a rapid increase in the use of pig models for human disease research. In addition to serving as xenotransplant organ donors and as tools in drug-design studies, pigs can also be used as model animals to study human developmental processes, congenital diseases, and disease-response mechanisms, thus making important contributions to improving human health. This review considers the current status and future applications of pigs as research models for studies of human cardiovascular diseases, cancer, ophthalmology, craniofacial, musculoskeletal, and skin research, reproductive and fetal development, nutrition, microbiome research, brain and neurodegenerative diseases, diabetes, infectious diseases, and vaccine design, as well as for xenotransplantation.