Yersinia pseudotuberculosis is a Gram-negative, zoonotic bacterium within the family Enterobacteriaceae. Clinical disease caused by Y. pseudotuberculosis is termed yersiniosis or pseudotuberculosis. Y. pseudotuberculosis is known for its role as a human enteric and foodborne pathogen, but it also commonly infects wildlife and domestic mammals. While clinical disease caused by Y. pseudotuberculosis more closely resembles that of Y. enterocolitica, it bears closer genetic similarity to Y. pestis. Since its discovery in 1883, the organism has undergone multiple taxonomic reclassifications and has been historically referred to as a Bacillus, a Pasteurella, and a Shigella species, in chronological order.