Pieter Johan van Berckel (January 1725 - 27 December 1800) was a Dutch politician, who served as mayor of Rotterdam and the first ambassador from the Dutch Republic to the United States of America. He also remained part of the government of Rotterdam until 30 January 1788, when he was dismissed by William V, Prince of Orange and the Estates General of the Dutch Republic - he never returned to Rotterdam and remained a refugee, dying in Newark.
He was born in Rotterdam, as a son of Engelbert van Berckel.
On 4 March 1783 Van Berckel was made the first minister plenipotentiaris to the USA. He set off for Philadelphia on 25th June on the Overijssel, accompanied by Gijsbert Karel van Hogendorp, Carel de Vos van Steenwijk and Johan Willem Simon van Haersolte, serving as an officer or sailing as a passenger on one of four ships, which formed an escort squadron. Van Berckel sent a letter ahead ordering a six-horse carriage, along with two Amsterdam merchants who wanted to invest in the Bank of Pennsylvania. He arrived on 11 October and was housed in the best inn in the city.
Van Berckel and the large Dutch delegation had taken fifteen weeks to cross the Atlantic due to bad weather along the coast. One of the four ships, the warship De Erfprins (launched in 1770 by the Admiralty of Amsterdam) was wrecked 25 miles off Cape Cod. She lost two masts in a storm and was adrift for nine weeks at sea before sinking on 25 November in the Atlantic. 40 survivors from a crew of 350 were eventually picked up by a US brig.
No horse, carriage or house were ready for Van Berckel, all of which severely offended him, as did the fact that the Congress was no longer in Philadelphia - Princeton had only 75 houses but several good inns, sufficient to house the 22 congressmen during its four months as the US capital. Van Berckel spent the night with a local grandee. Handing in his credentials to the Congress of the Confederation was postponed by a day by president Elias Boudinot, a silversmith, to give time for preparations - the ceremony happened on 31 October at Nassau Hall, now the library of the University of Princeton.