Banda Aceh is the provincial capital and largest city in the province of Aceh, Indonesia, located on the island of Sumatra, with an elevation of 35 meters. The city regency covers an area of 64 square kilometres and according to the 2000 census had a population of 219,070 people. Banda Aceh is located at the northwestern tip of Indonesia at the mouth of the River Krueng Aceh.

The city was originally named Kutaraja, and determined as the provincial capital in 1956. Kuta Raja means "City of the King", in reference to the founding of the Aceh Sultanate from Champa origins. Later its name was changed to Bandar Aceh Darussalam or popularly known as Bandar Aceh, with the first part of the name coming from the Persian bandar (بندر) meaning "port" or "haven". Today the city is spelled Banda Aceh with the lost of "r" in "Bandar". The city is also dubbed to as the "port to Mecca", and Aceh is also referred to as the "porch of Mecca" (Indonesian: Serambi Mekkah), since in the past during the days when the hajj pilgrims travelled by sea, the hajj pilgrim from all over Indonesian archipelago traditionally always make a stop over in the city before continuing their journey to Mecca. It is also known that earliest Southeast Asian Islamic sultanates — such as Samudra Pasai — were first established in Aceh, which means Islam first arrived in Aceh before spreading throughout Southeast Asia.

Aceh (/ˈɑːtʃeɪ/; [ʔaˈtɕɛh]) is a special region (Indonesian: daerah istimewa) of Indonesia, located on the northern tip of the island of Sumatra. Its first full name, Aceh Darussalam (1511–1959) then, Daerah Istimewa Aceh (1959–2001), Nanggroë Aceh Darussalam (2001–2009) and Aceh (2009–Present). Past spellings of its name include Acheh, Atjeh and Achin. The Aceh province has the highest proportion of Muslims in the country with regional levels of Sharia law.

It is thought to have been in Aceh where Islam was first established in Southeast Asia. In the early seventeenth century the Sultanate of Aceh was the most wealthy, powerful and cultivated state in the Malacca Straits region. Aceh has a history of political independence and fierce resistance to control by outsiders, including the former Dutch colonists and the Indonesian government. Aceh has substantial natural resources, including oil and natural gas—some estimates put Aceh gas reserves as being the largest in the world. Relative to most of Indonesia, it is a religiously conservative area.