Kilwa Kisiwani is an Islamic community on an island off the coast of East Africa, in present day Tanzania.

In the 9th century it was sold to a trader Ali bin Al-Hasan and over the following centuries it grew to be a major city and trading centre along that coast, and inland as far as Zimbabwe. Trade was mainly in gold and iron from Zimbabwe, ivory and slaves from Tanzania, and textiles, jewellery, porcelain, and spices from Asia.

By the 13th century, under the rule of the Mahdali family, Kilwa had become the most powerful city on the East African coast, and its influence stretched as far south as Mozambique. Abu Abdullah Ibn Battuta recorded his visit to the city around 1330, and commented favorably on the humility and religion of its ruler, al-Hasan ibn Sulayman.

In the early 16th century, Vasco da Gama extorted tribute from the wealthy Islamic state, but not soon after, another Portugese force took control of the island (1505), and it remained in Portugese hands until 1512, when an Arab mercenary captured Kilwa.The city regained some of its earlier prosperity, but in 1784 it came under the rule of the Omani rulers of Zanzibar. After the Omani conquest, the French built and manned a fort at the northern tip of the island, but the city itself was abandoned in the 1840s. It was later part of the colony of German East Africa from 1886 to 1918.

Serious archeological investigation began in the 1950s. In 1981 it was declared a World Heritage Site, and noted visitor sites are the Great Mosque, the Mkutini Palace and some remarkable ruins.