The Poland China is a breed of domestic pig, first bred in the Miami Valley, Ohio, United States, in 1816, deriving from many breeds including the Berkshire and Hampshire. It is the oldest American breed of swine. The Poland China hog was first bred on the Hankinson Farm in Blue Ball, Warren County, Ohio. A monument to this accomplishment still stands near the place where the hog was originally bred. The monument was moved slightly when the farm was sold for development of the Towne Mall, Middletown, Ohio in the early 1970s, and now stands across the street from the mall property on Cincinnati Dayton Road. Competing claims are made that the first Poland China breeder was David M. Magie, who lived at the Austin-Magie Farm near Oxford, Ohio.

It is very difficult to evaluate the exact contribution that any particular breed or type may have made to the breed that was formed from the crossing of many different kinds of breeding. It is difficult to imagine a breed of livestock owing a foundation debt to more different breeds than does the Poland China.

Poland China hogs are typically black, sometimes with six white patches, and are known for their large size. Big Bill, the largest hog ever recorded at 2,552 lb (1,157 kg), was a Poland China. Poland Chinas rank highest in U.S. pork production in pounds of hog per sow per year. The Poland China is unbeatable among various breeds of swine for the characteristic of maximum weight at any given age. The Poland Chinas are excellent feeders and they gain readily under conditions of good care and management. They are hogs that are very quiet in their dispositions and are rugged in their constitutions. The breed is known for having very substantial bone and for being sound in its feet and legs.

In the 1920s and 1930s, agricultural reformers introduced the Poland China pig into China, with mixed success. The pigs were not adapted to the climate, and Chinese farmers were more interested in a pig's ability to produce fertilizer than its meat capacity.