Govert Loockermans was born around 1616 in Turnhout, a village near Antwerp, Belgium. He left Holland on board the Soutberg (Salt Mountain), the ship which was bringing the newly-appointed Director, Wouter van Twiller, to New Netherland. During the voyage to New Netherland, the Soutberg captured a Spanish caravel, the St. Martin, and Loockermans transferred to that vessel and brought it safely to port.
Once Loockermans arrived in New Amsterdam, Director Van Twiller offered him a position with the Company, and he remained in that employment until 1639 when the Company opened up trading to private individuals. Govert Loockerman then returned to the Netherlands and obtained an appointment as the New Netherland agent for the mercantile house of Gillis Verbrugge and Company. Shortly afterward, he returned to New Amsterdam aboard the King David with a cargo of Gillis Verbrugge goods. He also set up a brewery on Pearl Street, near his home on Hanover Square.
In January 1642, Loockermans purchased the sloop, the Good Hope, from Isaac Allerton and began to trade north along the Hudson between New Amsterdam and Fort Orange (Albany), south on the Delaware River, and on the Sound to the mouth of the Connecticut River. While returning from one of his trading voyages to Albany in July 1644, he came under fire while passing the Rensselaerwyck patroonship and the resulting legal case, De Key v Coorn came before the Court of the Director and Council. Despite the inherent dangers, his business thrived–the growth of New Amsterdam and the river towns led to increased demand for goods from Holland. At the time of his death in 1671, he was one of the wealthiest citizens in New York.
Govert Loockermans was involved in Kieft's war against the Native Americans–on February 27, 1643, Director Kieft ordered Maryn Adriaensen and Govert Loockermans to lead a company of citizens in an attack on the Indian encampment at Corlears Hook. Thirty people, men, women and children, were killed while they slept under the protection of those they considered friends. Later in life, the recollection of his role in this terrible massacre was a cause of grief to Loockermans.
Loockermans was one of the Board of Nine Men, and was a signatory to the Great Remonstrance of New Netherland. In September 1651, Loockermans was charged with violating the revenue laws and was sentenced to banishment for three years, but this sentence was not enforced. Shortly after the Flushing Remonstrance was submitted to the authorities, Loockermans became involved in the cause of religious freedom and urged toleration for all. He was a Schepen (1657 and 1660), and was appointed to the Orphan Masters on September 10, 1663.
In 1666, Loockermans became a resident of New Utrech on Long Island and on July 13, 1670, he was commissioned Lieutenant of the New York militia. When Govert Loockermans died intestate in 1671, his son Jacob became the heir to his father's considerable landed estate in Maryland and his property in New York. His half-sister on his mother's side was Elsie Leisler and Jacob conveyed to Elsie's husband, Jacob Leisler, all the property he had inherited in New York.