Kiliaen Van Rensselaer (ca. 1580-1643) was a Dutch merchant and colonizer in America. A director of the Dutch West India Company, he was first patroon of Rensselaerswyck Manor in the colony of New Netherland.

Kiliaen Van Rensselaer was born in Amsterdam, probably in 1580. His early life is obscure. He entered the employ of a jeweler uncle who eventually retired in his favor, and by 1614 he was a leading Amsterdam diamond and pearl merchant. Prospering in East Indian trade, Van Rensselaer helped promote and found the West India Company, which was chartered in 1621 as a trading monopoly in Africa and America. As one of its directors, on two occasions he advanced sums to maintain the company's credit.

From the outset Van Rensselaer urged the company's fellow directors to develop New Netherland's agriculture rather than rely solely on the lucrative fur trade. When the company experienced difficulty securing settlers, Van Rensselaer utilized the Charter of Freedom and Exemptions, authorizing feudal estates for responsible Dutchmen promising to bring 50 adults to live on assigned tracts purchased from the Native Americans. Obtaining permission for such a patroonship in November 1629, he purchased land on the Hudson River near Albany from the Algonquin Indians. Later purchases expanded the area to approximately 700,000 acres on both sides of the river.

After patent to the manor of Rensselaerswyck was confirmed on Aug. 6, 1630, the first settlers soon arrived. Van Rensselaer zealously developed his New World estate, securing the most substantial group of settlers recruited by any patroon. He provided stock and farm tools for his colonists, purchased cattle, organized a manorial court, and sent a Calvinist pastor to care for the settlers' spiritual needs.

Anxious to develop agriculture in his barony, Van Rensselaer also sought benefits from fur trading. He advocated company restriction of this commerce to concessionaires, with his own agents controlling that in the Rensselaerswyck area. Vast correspondence shows his continued attention to administrative details (and probably price-rigging for settlers' supplies). However, company-licensed traders resisted efforts to forcibly collect tolls and restrict Indian commerce. Before his death in Amsterdam in October 1643, Van Rensselaer was plagued by settlers' disobedience to his appointed authorities and by agents' attempts to secure manors for themselves. Nevertheless, Rensselaerswyck proved the only successful patroonship during the Dutch era in New York.