Dutch naval commander and merchant remembered for his voyage in the Barents Sea region in search of an Arctic passage to India and for his victory over the Spanish fleet off Gibraltar, which led to an armistice between Spain and the United Provinces (now The Netherlands (Netherlands, The)) and brought about the Twelve Years' Truce (1609–21).

Under the direction of the Dutch navigator Willem Barents (Barents, Willem), van Heemskerck was master of a vessel that penetrated the Barents Sea in search of a northeast route to the Indies. After rounding Novaya Zemlya the ship became trapped in the ice, and the men were forced to spend the winter of 1596–97 on the island. Living in a hut made of driftwood, they were the first Europeans to survive a winter in the Arctic. They abandoned their still-icebound ship in June 1597 and left in two of the ship's open boats. Although van Heemskerck led most of the crew to safety, Barents died on the journey.

In 1598, van Heemskerck accompanied Jacob van Neck, a commercial representative of the Verre Company, on a trade mission to the East Indies. After van Neck returned home, van Heemskerck took over the fleet and established trade relations with the rulers of Ternate, Banda, and Amboina. In 1603 he captured the Portuguese treasure ship Santa Catarina in the Straits of Malacca. Appointed commander of the entire fleet of the United Provinces in 1607, he was killed while directing an attack that resulted in the dispersal of the Spanish fleet off Gibraltar.