Pieter Corneliszoon Plockhoy (also Pieter Cornelisz Plockhoy van Zierikzee or Peter Cornelius van Zurick-zee; c. 1625, possibly in Zierikzee, Netherlands – c. 1664–1670, Lewes, Delaware) was a Dutch Mennonite and Collegiant utopist who founded a settlement in 1663 near Horekill (Lewes Creek) on the banks of Godyn's Bay (Delaware Bay), near present-day Lewes, Delaware. The settlement was destroyed within a year via an English raid.
Almost nothing is known of Plockhoy's childhood and early life, but it is reasonable to assume he came from Zeeland and had a Mennonite background. In the early 1660s he lived at Amsterdam, where he became associated with the struggle of the liberal Mennonites, who were influenced by Collegiantism and were led by Galenus Abrahamsz de Haan, against the conservative Mennonites.
Before embarking for the New World, Plockhoy unsuccessfully petitioned Oliver Cromwell in 1658 for support in establishing various ideal settlements in England. It's possible that he worked in the circle of the intellectual Samuel Hartlib, who was certainly aware of his utopian plans. Plockhoy published political pamphlets addressing contemporary social problems in 1658 and collaborated with Franciscus van den Enden in plans for founding a new society in New Netherland. Some contemporary writers that were critical of his views alleged that Plockhoy defended polygamy. Plockhoy moved back to the Netherlands in 1661. He entered into a contract with the Dutch government to create a settlement along the southern part of the Delaware River.
In 1663 Plockhoy and 41 settlers made their way to Delaware Bay and established their colony near the former Zwaanendael Colony. It is not known whether he survived the 1664 English raid on his settlement, but he is generally thought to have died within a few years of that event. Plockhoy's wife, his blind son, Cornelis, and several of the other original colonists continued to live in Lewes. In 1694 a blind man named Cornelis Plockhoy moved to Germantown, Pennsylvania. Although older sources usually identified this man as the aged Pieter Cornelisz Plockhoy, current writers generally agree that this was his son, Cornelis.
- "Brief and Concise Plan Intended to be a Mutual Agreement for Some Colonists Willing to go to the South River in New Netherland". World Digital Library. 1662. Retrieved 2013-06-16.
- Plantenga, Bart. "The Mystery of the Plockhoy Settlement in the Valley of Swans". Mennonite Historical Bulletin (April 2001). Archived from the original on 21 December 2010. Retrieved 13 March 2011.
- "Plockhoy's Social Plans in the Old and New World". Retrieved 13 March 2011.
- Harder, Leland. "Pieter Plockhoy Revisited". Mennonite Life (March 2005). Archived from the original on 16 June 2011. Retrieved 13 March 2011.