During the Dutch Revolt (1568–1648), the Dunkirkers or Dunkirk Privateers were commerce raiders in the service of the Spanish monarchy and later the Kingdom of France. They were also part of the Dunkirk fleet, which consequently was a part of the Spanish monarchy's Flemish fleet (Armada de Flandes). The Dunkirkers operated from the ports of the Flemish coast: Nieuwpoort, Ostend, and Dunkirk. Throughout the Eighty Years' War, the fleet of the Dutch Republic repeatedly tried to destroy the Dunkirkers. The first Dunkirkers sailed a group of warships outfitted by the Spanish government, but non-government investment in privateering soon led to a more numerous fleet of privately owned and outfitted warships.

Commerce raiding is a form of naval warfare used to destroy or disrupt logistics of the enemy on the open sea by attacking its merchant shipping, rather than engaging its combatants or enforcing a blockade against them.