Adriaen (Aerjan) Block (c. 1567 – buried April 27, 1627) was a Dutch private trader and navigator who is best known for exploring the coastal and river valley areas between present-day New Jersey and Massachusetts during four voyages from 1611 to 1614, following the 1609 expedition by Henry Hudson. He is noted for possibly having named Block Island, Rhode Island, and establishing early trade with the Native Americans, and for the 1614 map of his last voyage on which many features of the mid-Atlantic region appear for the first time, and on which the term New Netherland is first applied to the region. He is credited with being the first European to enter Long Island Sound and the Connecticut River and to determine that Manhattan and Long Island are islands.
Though spending much of his time at sea, Block called Amsterdam his home. There, on October 26, 1603, he married Neeltje Hendricks van Gelder, with whom he would have five children between 1607 and 1615. In 1606 they moved into a house called De Twee Bontecraijen ("The Two Hooded Crows") on Amsterdam's Oude Waal street, where they would live the rest of their lives.
In the 1590s, Block already was active in the shipping trade, transporting wood from Northern Europe to deforested Spain. He is for example mentioned delivering Norwegian wood in April 1596 in Bilbao. From there he headed for Ribadeo to buy goods for Cádiz. In April 1601, he was part of a convoy of ships leaving Amsterdam for the Dutch East Indies, at that time probably as far as the Moluccas, returning home in 1603.
In the spring of 1604, after delivering goods in Liguria, Block sailed on to Cyprus buying goods (rice, cotton, nuts, etc.) he hoped to sell in Venice. This trade fell through, and he headed home to Amsterdam. Passing Lisbon, he came upon a Lübeck-based ship returning from a trip to Brazil. He had written permission from Dutch authorities to capture enemy ships, which he put to use, taking the ship and its load to Amsterdam. Though the ship and some of its goods were returned to its owners, Block made a lot of money, with which he probably bought the house on the Oude Waal.