Scimitar-horned Oryx primarily inhabits sub-desert, arid steppes, annual grasslands, lightly wooded inter-dunal depressions and vegetated ephemeral watercourses, rarely entering true desert or dense Sahelian bush (Devillers and Devillers-Terschuren 2005, Morrow et al. 2013).

Scimitar-horned Oryx probably once occurred throughout most of the sub-desert zones north and south of the Sahara. In Egypt, the historical range included parts of the Western Desert, west of the River Nile, but mostly around oases (Osborn and Helmy 1980). In Libya the species was reported to occur in the Fezzan (southwest) and Kufra (southeast), close to known populations in northern Chad and the western Egypt and also the northeast, but there are no confirmed specimens of the species (Hufnagl 1972, Khattabi and Mallon 2001). Scimitar-horned Oryx was very rare in extreme southern Tunisia (Lavauden 1920), although some authors doubt that an established population existed and there are no first-hand reports or reliably sourced specimens (Morrow et al. 2013 and references therein). In Algeria, they were found in the south and vagrants likely occurred north of the Sahara (De Smet and Smith 2001). The species formerly occurred in southern Morocco and Western Sahara (Aulagnier et al. 2001, Cuzin et al. 2007). In the Sahel, it was found in northern Senegal, south and western Mauritania, central Mali, northern Burkina Faso, central and southern Niger), central and northern Chad, and central Sudan (Darfur and Kordofan), in several places moving north into the desert zone following seasonal rainfall and availability of good pastures (East 1999, Devillers and Devillers-Terschuren 2005, Morrow et al. 2013). Occurrence in far northeastern Nigeria may have been only seasonal (East 1999).

Scimitar-horned Oryx reportedly became extinct in Egypt in the 1850s–1860s (Osborn and Helmy 1980), in Libya in the 1940s (Newby 1988), Algeria in the 1960s (apart from two possible vagrants in 1987; De Smet and Smith 2001), Tunisia by 1906 (Lavauden 1924), Morocco in the 1930s, and Western Sahara in the 1950s (Aulagnier et al. 2001).

In the Sahel region, the species became extinct in Senegal by 1914 (Sournia and Dupuy 1990), Mauritania in the 1960s, Mali in 1983, Burkina Faso in the 1950s, Niger in 1986, and Sudan in the mid-1970s (East 1999, Newby 1988, Morrow et al. 2013). Scimitar-horned Oryx survived longest in Chad where more than 3,500 were estimated to occur in 1973–1978, but only a few dozen remained by 1988) and several subsequent surveys failed to locate any surviving animals (Newby 1988, Morrow et al. 2013). Reliable eye-witness reports indicate the last male was shot in the Ouadi Kharma district in 1989 (J.E. Newby, in litt.).

Scimitar-horned Oryx has been successfully reintroduced to Ouadi-Rimé-Ouadi Achim Faunal Reserve in Chad. The first animals were released into the wild in August 2016, with eight further groups released up to March 2022.

The species has also been re-established in two fenced, and two partly fenced protected areas in Tunisia (Bou Hedma N.P. in 1985, Sidi Toui N.P. in 1999, Oued Dekouk N.R. in 1999, Dghoumes N.P. in 2007), and two in Senegal (Guembeul Faunal Reserve, Ferlo Faunal Reserve in 1998) as part of long-term reintroduction programmes.

The Scimitar-horned Oryx is listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and Appendix I of the Convention  on the Conservation of Migratory Species of Wild Animals (CMS). It is included in the CMS Sahelo-Saharan Megafauna Concerted Action (SSMF). A revised action plan for the eight species listed in the SSMF is scheduled for completion by early 2023.

There are national strategies to restore the species in Tunisia (DGF 2001) and Morocco (Cuzin et al. 2007).

Reintroduction to Chad
An ambitious project to re-establish Scimitar-horned Oryx to the wild began in the early 2000s. A series of surveys to assess oryx status and habitat availability across former oryx range in several states was followed by a preliminary workshop held in Al Ain, UAE in 2009 and stakeholder workshops in Algiers, Algeria in 2010 and N’Djamena, Chad in 2012. The N’Djamena workshop was attended by a wide range of stakeholders including government officials, local leaders,  and international experts. The workshop recommendations included the rehabilitation of Ouadi Rimé-Ouadi Achim Faunal Reserve and reintroduction of Scimitar-horned Oryx, and received the support of the President of Chad. A technical meeting was held later in 2012 in Abu Dhabi to develop an initial proposal for the reintroduction of scimitar-horned oryx into the Ouadi Rimé-Ouadi Achim Faunal Reserve in Chad.

The Scimitar-horned Oryx Reintroduction Programme is a joint initiative of the Government of Chad and the Environment Agency–Abu Dhabi (EAD), implemented on the ground by SaharaConservation (formerly Sahara Conservation Fund) in partnership with the Ministry for the Environment, Fisheries and Sustainable Development, with technical support from Fossil Rim Wildlife Center, National Zoo Smithsonian Conservation Biology Institute, Zoological Society of London, and others.

In March 2016, the first group of captive-bred oryx was transferred from Abu Dhabi to Chad and placed in a large (46 ha) acclimatisation enclosure constructed in Ouadi Rimé-Ouadi Achim Faunal Reserve. The first release occurred in August 2016 when 21 Scimitar-horned Oryx were released into the wild. The first wild birth was recorded in September 2016. Each released individual was fitted with a GPS satellite collar. Between August 2016 and March 2022, 263 founder animals and 22 young born in the acclimatisation enclosure have been released, in nine groups. Since the first release into the wild, some 331 wild-born oryx had been recorded up the end of 2021.

EAD has supported comprehensive genetic studies of SHO at the Royal Zoological Society of Scotland’s WildGenes Laboratory as part of establishing and curating the “World Herd” in Abu Dhabi which is assembled from the global ex-situ population. The herd is managed in a purpose-built captive breeding facility to provide genetically diverse source animals for release. EAD also arranges the flights to transport the oryx and supplies to Chad. Over 10 years, the genetic diversity present in key source populations was analysed using three genetic datasets (mitochondrial DNA sequence, nuclear DNA microsatellite and SNP markers) taken from over 500 individuals in public and private institutions to ensure that the founders represented the greatest breadth of generic diversity available (Ogden et al. 2020).

The released population in Ouadi-Rimé-Ouadi Achim Faunal Reserve is protected by government rangers and is monitored through tracking of satellite collars, aerial counts, and ground survey missions.

Oryx intended for release are deparasited on a regular basis and vaccinated between 2 and 6 months before translocation to in Chad against Peste des Petits Ruminants, sheep and goat pox, the Pasteurella / Mannheimia / Clostridium complex, Contagious Caprine Pleuropneumonia, Foot and Mouth Disease and Rift Valley Fever, both for their own protection and to prevent transmission of disease to domestic livestock and other wild animals in Chad (Pesci 2022).

Tunisian metapopulation
The number of Scimitar-horned Oryx in each protected area is 40–100 and these populations are considered too small to be individually sustainable in the long-term. The current approach to SHO management in Tunisia follows  a metapopulation strategy which is considered the most pragmatic option and an intermediate step before fully free-ranging herds can be re-established. The proposed metapopulation management strategy requires additional translocations of SHO between protected areas (Petretto et al. 2020). Management is carried out by the government agency, the Direction Générale des Forêts (DGF), supported by Marwell Wildlife. The oryx have been genetically sampled by Marwell Wildlife and the WildGenes Laboratory of RZSS and the results used in Population Viability Analysis (PVA) models to project the impact of different management decisions on population persistence and retention of genetic diversity in individual populations and across the Tunisian metapopulation (Petretto et al. 2020).

Proposed reintroductions
The semi-managed population of Scimitar-horned Oryx in the Arrouais enclosure of Souss-Massa N.P., Morocco, was established to provide stock for reintroductions into the wild, in accordance with the national strategy (Cuzin et al. 2007). Some oryx have been transferred to other breeding and acclimatisation centres in the country in preparation for future releases.

In Senegal, Scimitar-horned Oryx are held in the fenced Katane enclosure (12 km²) inside Ferlo Nord Faunal Reserve, and at Guembeul Faunal Reserve, with the aim of release into the wild at some point in in the future.

A feasibility study has been conducted on the reintroduction of Scimitar-horned Oryx to Gadabédji Biosphere Reserve, Niger (Lamarque et al. 2009) and implementation is currently under discussion.

Ex situ populations
As of 31 December 2021, the number of Scimitar-horned Oryx registered in the International Studbook was 3,465 animals (1,505 males, 1,892 females, 68 young) in 176 institutions across the world (Gilbert 2022). Scimitar-horned Oryx in the North American, European, and Australasian regions are managed in three coordinated breeding programmes. In addition, there are up to 4,000 in collections in the Arabian Peninsula (Gilbert 2015) and over 7,000 on Texas ranches (https://www.conservationcenters.org/spa-species.html).

The Source Population Alliance (SPA) is a group of private landowners, conservation centres, and zoos who combine smaller ex-situ populations in the USA, Canada, and Australia to create a larger 'metapopulation' as a resource for potential reintroductions and as an insurance against extinction. Scimitar-horned Oryx was one of the four original species in the SPA programme.

Scimitar-horned Oryx are also kept on some private game ranches in South Africa, but the number is unknown.

Most of the animals in the International Studbook and in Texas are thought to be descended from 40–50 founders originating in Chad (Gilbert 2022).