Algeria, officially the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. The country is the largest country by total area in Africa and in the Arab world, and is bordered to the northeast by Tunisia; to the east by Libya; to the southeast by Niger; to the southwest by Mali, Mauritania, and Western Sahara; to the west by Morocco; and to the north by the Mediterranean Sea. It has a semi-arid geography, with most of the population living in the fertile north and the Sahara dominating the geography of the south. Algeria covers an area of 2,381,741 square kilometres (919,595 sq mi), making it the world's tenth largest nation by area, and the largest nation in Africa. With a population of 44 million, Algeria is the ninth-most populous country in Africa, and the 32nd-most populous country in the world. The capital and largest city is Algiers, located in the far north on the Mediterranean coast.

Pre-1962 Algeria has seen many empires and dynasties, including ancient Numidians, Phoenicians, Carthaginians, Romans, Vandals, Byzantines, Umayyads, Abbasids, Rustamids, Idrisids, Aghlabids, Fatimids, Zirids, Hammadids, Almoravids, Almohads, Zayyanids, Spaniards, Ottomans and finally, the French colonial empire. The vast majority of Algeria's population is Arab-Berber, practicing Islam, and using the official languages of Arabic and Berber. However, French serves as an administrative and educational language in some contexts. The main spoken language is Algerian Arabic.

Algeria is a semi-presidential republic, with local constituencies consisting of 58 provinces and 1,541 communes. Algeria is a regional power in North Africa, and a middle power in global affairs. It has the highest Human Development Index of all non-island African countries and one of the largest economies on the continent, based largely on energy exports. Algeria has the world's sixteenth-largest oil reserves and the ninth-largest reserves of natural gas. Sonatrach, the national oil company, is the largest company in Africa, supplying large amounts of natural gas to Europe. Algeria's military is one of the largest in Africa, and has the largest defence budget on the continent. It is a member of the African Union, the Arab League, the OIC, OPEC, the United Nations, and the Arab Maghreb Union, of which it is a founding member.