Johan de Graeff (October 29, 1673 in Amsterdam – April 12, 1714) - Lord of the semisouverain Fief Zuid-Polsbroek and Lord of the castle Ilpenstein - was a member of the De Graeff - family from the Dutch Golden Age.
He was the oldest son of Pieter de Graeff and Jacoba Bicker, his elder brother was Cornelis de Graeff II., Baron of Purmerland and Ilpendam, and De Graeffs younger sister Agneta de Graeff, who married to Jan Baptiste de Hochepied, lives in a City-Palace today called Kabinet der Koningin.
After his studies at the University of Leiden in the year 1699, he became an advisor and from 1709 to 1714 a member of the vroedschap of the City of Amsterdam.
De Graeff residence at the Herengracht in a house now called Tassenmuseum Hendrikje, at castle Ilpenstein and at Bronstee, a Countryhouse near Heemstede.
In the year 1709 Johan married Johanna Hooft, they had five children:
Johan de Graeff has a big art collection including paintings from Rembrandt van Rijn, Gerard Ter Borch and Jacob van Ruisdael. The collection know three very famous pictures, Catharina Hooft with her Nurse, painted by Frans Hals, Jacob Blessing the Sons of Joseph and Portrait of Andries de Graeff, both from Rembrandt.