The Acehnese (Jawi: اورڠ اچيه‎), also written as Atjehnese and Achinese, are an indigenous ethnic group native to Aceh, a province on the northernmost tip of the island of Sumatra in Indonesia.

[7] The Acehnese people are also referred to by other names such as Lam Muri, Lambri, Akhir, Achin, Asji, A-tse and Atse.

[14][7] Aceh came to international attention as being the hardest-hit region of the 2004 Indian Ocean earthquake with 120,000 people dead.

Foreign ethnic groups, especially Indians, as well as a small amount of Arabs, Persians, Turks, and Portuguese also compromise the ancestry of the Acehnese people.

Linguist Paul Sidwell wrote that "Sometime during this early phase of language shift, perhaps before the beginning of Common Era, the Chamic speakers who were to become the Acehnese left the mainland on a journey that would ultimately end in northern Sumatra."

Using Graham Thurgood's thesis, Sidwell argues that the Acehnese likely had been separated from Chamic-speaking peoples around the first to second century BCE.

[18] Chinese and Indian sources from 500 CE and onward mention that there was a settlement in northernmost Sumatra (Aceh) which was called P'o-lu.

By the sixteenth century, Aceh was an important cultural and scholastic Islamic center influential throughout much of Southeast Asia.

[21] The mixed population of Acehnese-Minangkabau people is also found in the southern region, namely in the areas around Susoh, Tapaktuan and Labuhan Haji.

[30] Numerous place names of Sanskrit origin (for example, Indrapuri, Aceh Besar) reflects the cultural heritage of Hinduism in the past.

[27] Seunagan district for an instance, is well known to this today for numerous of ulamas of the Sayyid descent, of which the local community would address them with the title Teungku Jet or Habib as a form of respect.

[33] Many of their descendants today have intermarried with the natives Acehnese people and do no longer bear their clan names.

[34][35] At present, people of Persian and Turkish descent in Indonesia are mostly scattered in Aceh Besar Regency.

Portuguese sailors under the lieutenant leadership of Captain Pinto, were sailing towards Malacca, stopped by and traded there; where some of them remained and settled there.

History records that this event occurred between 1492 and 1511; of which at that time the area was under the rule of a small kingdom called Lamno, with King Meureuhom Daya as their ruler.

Other Mon-Khmer loanwords are only found in Acehnese, which suggests that after the split from the Chamic core area, the forebears of the Acehnese people might have lived in the Malay Peninsula or Southern Thailand where they picked up these loanwords from neighboring Mon-Khmer speakers before migrating to Sumatra.

[38] Dialects on the east coast of Pidie Regency and in southern Daya tend to be more homogeneous, so much so that it is co-related with the migration that came along with the expansion of power of the Aceh Sultanate after the 1500s.

[40] Likewise, the Acehnese language is also commonly used in everyday affairs that are organized by government agencies in Aceh.

[44] Several types of traditional recipe use a blend of cannabis as a flavoring spice; such cases are also found in the cuisine of some other Southeast Asian countries, such as Laos.