Cairo (/ˈkaɪroʊ/ kye-roh ; Arabic: القاهرة‎) is the capital of Egypt and the largest city in the Middle-East and second-largest in Africa after Lagos. Its metropolitan area is the 15th largest in the world. Located near the Nile Delta, it was founded in 969 CE. Nicknamed "the city of a thousand minarets" for its preponderance of Islamic architecture, Cairo has long been a center of the region's political and cultural life. Cairo was founded by Jawhar al-Siqilli "The Sicilian", of the Fatimid dynasty, in the 10th century CE, but the land composing the present-day city was the site of national capitals whose remnants remain visible in parts of Old Cairo. Cairo is also associated with Ancient Egypt as it is close to the ancient cities of Memphis, Giza and Fustat which are near the Great Sphinx and the pyramids of Giza.

Egyptians today often refer to Cairo as Maṣr ([mɑsˤɾ], مصر), the Egyptian Arabic pronunciation of the name for Egypt itself, emphasizing the city's continued role in Egyptian influence. Its official name is القاهرة al-Qāhirah , means literally: "the Defeater", in reference to the fact that the planet Mars ("Al Najm Al Qahir") was rising at the time when the city was founded as well as, "the Vanquisher"; "the Conqueror"; Egyptian Arabic pronunciation: [elqɑ(ː)ˈheɾɑ], "the Defeater" or, " "the Victorious" (al-Qahira) in reference to the much awaited Caliph al-Mu'izz li Din Allah who arrived from the old Fatimid capital of Mahdia in 973 to the city. The Egyptian name for Cairo is said to be: Khere-Ohe, meaning: "The Place of Combat", supposedly, in reference to a battle which took place between the Gods Seth and Horus. Sometimes the city is informally also referred to as كايرو Kayro [ˈkæjɾo]. It is also called Umm al-Dunya, meaning "the mother of the world".

Cairo has the oldest and largest film and music industries in the Arab world, as well as the world's second-oldest institution of higher learning, al-Azhar University. Many international media, businesses, and organizations have regional headquarters in the city; the Arab League has had its headquarters in Cairo for most of its existence.

With a population of 6.76 million spread over 453 square kilometers (175 sq mi), Cairo is by far the largest city in Egypt. With an additional 10 million inhabitants just outside the city, Cairo resides at the center of the largest metropolitan area in Africa and the Arab World as well as the 18th-largest urban area in the world. Cairo, like many other mega-cities, suffers from high levels of pollution and traffic. Cairo's metro, one of only two metros on the African continent, ranks among the fifteen busiest in the world, with over 1 billion annual passenger rides. The economy of Cairo was ranked first in the Middle East in 2005, and 43rd globally by Foreign Policy's 2010 Global Cities Index.