Swahili or Kiswahili (known in Swahili itself as Kiswahili) is a Bantu language spoken by various ethnic groups that inhabit several large stretches of the Mozambique Channel coastline from northern Kenya to northern Mozambique, including the Comoro Islands. It is also spoken by ethnic minority groups in Somalia. Although only five million people speak Swahili as their mother tongue, it is used as a lingua franca in much of East Africa, meaning the total number of speakers exceeds 60 million. Swahili serves as a national, or official language, of five nations: Tanzania, Kenya, Uganda, the Comoros and the Democratic Republic of the Congo.

Some Swahili vocabulary is derived from Arabic through more than twelve centuries of contact with Arabic-speaking inhabitants of the coast of southeastern Africa. It has also incorporated Persian, German, Portuguese, English, and French words into its vocabulary through contact during the past five centuries.

Scholars lack sufficient historical or archaeological evidence to allow them to state exactly when and where either the Swahili language or the Swahili culture emerged. Nevertheless, it is assumed that the Swahili speaking people have occupied their present territories, hugging the Indian Ocean, since well before 1000 CE. Arab traders are known to have had extensive contact with the coastal peoples from at least the 6th century CE, and Islam began to spread along the East African Coast from at least the 9th century.