The Barbary pirates, Barbary corsairs, or Ottoman corsairs were mainly Muslim pirates and privateers who operated from the Barbary states. This area was known in Europe as the Barbary Coast, in reference to the Berbers. Slaves in Barbary could be of many ethnicities, and of many different religions, such as Christian, Jewish, or Muslim. Their predation extended throughout the Mediterranean, south along West Africa's Atlantic seaboard and into the North Atlantic as far north as Iceland, but they primarily operated in the western Mediterranean. In addition to seizing merchant ships, they engaged in razzias, raids on European coastal towns and villages, mainly in Italy, France, Spain, and Portugal, but also in the British Isles, the Netherlands, and Iceland.

A privateer is a private person or vessel which engages in maritime warfare under a commission of war. Since robbery under arms was a common aspect of seaborne trade, until the early 19th century all merchant ships carried arms. A sovereign or delegated authority issued commissions, also referred to as letters of marque, during wartime. The commission empowered the holder to carry on all forms of hostility permissible at sea by the usages of war. This included attacking foreign vessels and taking them as prizes and taking crews prisoner for exchange. Captured ships were subject to condemnation and sale under prize law, with the proceeds divided by percentage between the privateer's sponsors, shipowners, captains and crew. A percentage share usually went to the issuer of the commission.