The native Makassar, Macassar, Makassarese, Makassan (in Thai), or Macassan (in Australian English), are one of the Austronesian people native to the southern Celebic peninsular regions (concentrated around the Makassar area) of Sulawesi Island in Indonesia. The Makassar people are rich in culture and they are acknowledged for their traditional culinary and maritime knowledges, together with the Bugis, its closest related ethnic group. The Makassar people speak various native Makassaric languages, with Standard Makassar being the prominent or popular one, they also mastered in non-Makassaric languages such as Indonesian (both Standard Indonesian and Makassar Indonesian) and relatively decent English (especially Australian English and American English).

The Phinisi, a worldwide well-known boatbuilding of Southern Sulawesi-origin, a joint invention of Bugis-Makassar people, is internationally inscribed as the Intangible Cultural Heritage of Humanity by the United Nations Educational, Scientific and Cultural Organization (UNESCO).

The Makassar people are amongst the first native people who are endowed with the harvesting and processing knowledge of holothuroidea (sea cucumber, natively found between the Wallace and Weber line), and was spread to another regions beyond its native homeland throughout the Indonesian Archipelago to the Oceania (and some another regions of Asia–Pacific) due to their seafaring activity (mostly departed from Makassar port in Makassar Strait), their knowledge is better-known as trepanging (in Australian English), rooted from the native Makasar word “taripang” (lit. 'sea cucumber'). Furthermore, the knowledge in fauna sector is not an exception, the Makassar oil is one of it, a herbal oil extracted from their own Makassar ebony (mixed with another herbal ingredients), was famously used for haircare treatment amongst the Western Europeans. In several Oceanic countries, one of the ingredients for Makassar oil, the Cananga odorata, are still famously known as “Makassar” (but spelt in different orthographical rules of each respective country, such as Mokasoi in Fiji, Mohokoi in Tonga, Mosoʻoi in Samoa, etc.). Almost all Makassar trade activity was recorded as one of the important historical inter-native relationship and businesses of ancient times (especially with the Aboriginal Australians and several Oceanian natives).

Nowadays, the Makassar diaspora could be found across regions beyond their native homeland in southern Sulawesi; in Indonesia itself, the Makassar diaspora could be found in several regions of the Nusa Tenggara islands, the Pangkajene islands, parts of Sangkarang and Kangean archipelagoes, the Selayar Islands, the Sumenep and Pamekasan regions of Madura, parts of Kalimantan island, and so on. Meanwhile outside of Indonesia, the diasporic Makassar community could be found in Insular Southeast Asia and its vicinity (such as Australia, Thailand, etc.), as well as some African countries (such as Mozambique in Eastern Africa and South Africa in Southern Africa). It is also believed that the Makassar people migrated to Madagascar (with the migration route starting from Southern Sulawesi to Southern Kalimantan, next to Java around Sunda Strait, and then to Madagascar).

The Makassar are an ethnic group originally from the southern coast of the island of Sulawesi. Their exploratory spirits have led to successful overseas explorations. This is exemplified by the Kingdom of Gowa (14-17th century), which succeeded in forming a vast Islamic empire with a large and strong naval force. Its territory included almost the entire island of Sulawesi, eastern Kalimantan, East Nusa Tenggara, part of West Nusa Tenggara, part of Maluku and some small surrounding islands. The Makassar people made treaties with Bali and cooperated with Malacca and Banten, as well as some other kingdoms within the archipelago. Similar treaties were sometimes struck with foreign powers, especially with the Portuguese. However, until its fall, Gowa was also engaged in ongoing wars with the Netherlands.

The Makassar are known to have explored large sections of the world's oceans, reaching as far as South Africa. In South Africa there is an area called “Macassar”. It is suspected that the local population is of mixed indigenous and Makassar descent. Meanwhile, the name Maccassar is likely to have originated from the name for their ancestors' homeland. There are several places named Maccassar in South Africa and neighbouring Mozambique.

Makassar trepangers from the southwest corner of Sulawesi visited the coast of northern Australia in the eighteenth and nineteenth centuries to collect and process trepang (also known as sea cucumber), a marine invertebrate prized for its culinary and medicinal values in Chinese markets. The term Makassan (or Macassan) is generally used to apply to all the trepangers who came to Australia, although some were from other islands in the Indonesian Archipelago, including Timor, Rote and Aru.

Fishing fleets began to visit the northern coasts of Australia from Makassar in southern Sulawesi, Indonesia from about 1720, but possibly earlier. While Campbell Macknight's classic study of the Makassan trepang industry accepts the start of the industry as about 1720, with the earliest recorded trepang voyage made in 1751, Regina Ganter of Griffith University notes a Sulawesi historian who suggests a commencement date for the industry of about 1640. Ganter also notes that for some anthropologists, the extensive impact of the trepang industry on the Yolngu people suggests a longer period of contact. Arnhem Land rock art, recorded by archaeologists in 2008, appears to provide further evidence of Makassan contact in the mid-1600s. Contact has even been proposed from as early as the 1500s.