Agneta de Graeff van Polsbroek

Agneta de Graeff van Polsbroek (Amsterdam, 10 November 1603 - 3 or 4 March 1656), was a patrician woman from the Dutch Golden Age. She became famous as the mother-in-law of Johan de Witt.

Agneta was born as the oldest daughter of Jacob Dircksz de Graeff and Aeltje Boelens Loen (? - 1620). In 1625 she was married to Jan Bicker. The couple had two daughters: Wendela Bicker and Jacoba Bicker; the first married Johan de Witt and the second married her cousin Pieter de Graeff. The couple lived at their country houses De Eult at Baarn, Akerendam and Duynwijck in Beverwijk. Between the city of Amsterdam they owned a cityhause at Herengracht and an island, called Bickerseiland. In 1663/64 Agneta was painted by Wallerant Vaillant. Her tomb chapel is located at the Westerkerk.