The scimitar oryx (Oryx dammah), also known as the scimitar-horned oryx and the Sahara oryx, is a Oryx species that was once widespread across North Africa. In 2000, it was declared extinct in the wild on the IUCN Red List.

A captive bred group was released into an acclimation enclosure within the Ouadi Rimé-Ouadi Achim Faunal Reserve in 2016, then reintroduced into the wild. An additional 21 individuals were released into the acclimation enclosure in 2017. The first ones to be relocated were released into the wild in 2016 and have adapted well to their surroundings. In 2017, another herd of 75 scimitar-horned oryxes arrived in an operation led by Chad's Ministry of Environment and Fisheries and the Sahara Conservation Fund. In 2021, 60 new calves were born, bringing the number in the wild to about 400. This particular oryx can survive for months or even years without drinking water. A grazing animal, it derives most of its daily moisture intake from plants.

The scimitar oryx has a long taxonomic history since its scientific description in 1816 by Lorenz Oken, who named it Oryx algazel. This antelope stands a little more than 1 m (3.3 ft) at the shoulder. The males weigh 140–210 kg (310–460 lb) and the females weigh 91–140 kg (201–309 lb). The coat is white with a red-brown chest and black markings on the forehead and down the length of the nose. The calves are born with a yellow coat without distinguishing marks; their coats change to adult coloration at 3–12 months old.

The scimitar oryx formed herds of mixed sexes of up to 70 members, usually guided by the bulls. They inhabited semideserts and deserts and were adapted to live in extreme heat, with their efficient cooling mechanism and very low requirement of water. Scimitar oryx feed on foliage, grasses, succulent plants, and plant parts during the night or early morning. Births peak between March and October. After a gestation of 8-9 months, one calf is born. Soon after, the female has a postpartum estrus.

The decline of the scimitar oryx population began as a result of climate change during the Neolithic period, and later it was hunted extensively for its horns. Today, it is bred in captivity in special reserves in Tunisia, Morocco, and Senegal, and on private exotic animal ranches in the Texas Hill Country. In 2016, a reintroduction program was launched and currently a small herd has been successfully reintroduced in Chad.

The scimitar oryx was domesticated in Ancient Egypt and is believed to have been used as food and sacrificed as offerings to gods. Wealthy people in Ancient Rome also bred them. The use of their valuable hides began in the Middle Ages. The unicorn myth may have originated from sightings of a scimitar oryx with a broken horn.

The scimitar oryx was the emblem of the ancient Egyptian Oryx nome and today is the animal symbol of the Sahara Conservation Fund.