Nicholas van Hoorn (c. 1635 in Vlissingen – buried 24 June 1683, in Isla Mujeres) was a merchant sailor, privateer and pirate. He was born in the Netherlands and died near Veracruz after being wounded on the Isla de Sacrificios. Nikolaas or Klaas was engaged in the Dutch merchant service from about 1655 until 1659, and then bought a vessel with his savings. With a band of reckless men whom he had enlisted, he became a terror to the commerce of the Dutch Republic and the Spanish Empire. Later he had several ships in his employment and obtained such notoriety that some governments were willing to employ him against their enemies.