The Ossabaw Island hog, or Ossabaw Island, is a breed of pig derived from a population of feral pigs on Ossabaw Island, Georgia, United States. The original Ossabaw hogs are descended from swine released on the island in the 16th century by Spanish explorers. A breeding population has been established on American farms off the island, but they remain a critically endangered variety of pig. As the breed is not commercially farmed, and no longer studied in any numbers of depth, details of their breeding lives and habits is hard to find. Since 1978 the island has been owned by the State and managed by the Georgia Department of Natural Resources (DNR) as a preserve.

They are small swine, less than 20 inches (510mm) tall and weighing less than 200lbs (90kg) at maturity. This size is partly due to the phenomenon of insular dwarfism, and individuals kept in off-island farms may grow slightly larger in successive generations. They are also hardy and very good foragers, making them useful in free-range farming (as opposed to intensive pig farming).

As a result of life on an island where the abundance and scarcity of food is seasonally variable, Ossabaw hogs store fat in a different manner than most domestic pigs and have a "thrifty gene". In conditions with constant supplies of food (such as on farms and in the laboratory) they accrue more fat than other pigs and may develop a "prediabetes" condition. Because this trait makes them useful as a model organism, scientific studies on metabolic syndrome and Type II diabetes have been conducted on the Ossabaw hog. Ossabaw hogs also have adapted to the high salt diets and minimal availability of fresh water on the island.

Ossabaw hogs appear in a wide range of colours, with the most common being black and a spotted variety. They additionally have long snouts, upright ears, and a heavy coat of bristles compared to other pig breeds. Ossabaws are noted to be intelligent and friendly swine in terms of temperament. The meat of Ossabaws is dark, with a unique texture, and is prized for resembling the jamón ibérico of the black Iberian pig.

Both the island and mainland populations continue to be considered vulnerable by the ALBC, Slow Food, and others. The breed is listed as "critical" on the priority list of the American Livestock Breeds Conservancy, and is also included in Slow Food USA's Ark of Taste, a catalogue of heritage foods in danger of extinction.