Pieter Claesz. van Ruijven (Delft, 1624 - Delft, August 7, 1674) is best known as Johannes Vermeer's patron for the better part of the artist's career.
Van Ruijven was the son of a brewer and a Remonstrant. In 1653 he married Maria de Knuijt. The couple had one daughter named Magdalena, born in 1655. Like his father, he worked for the city institution, the Camer van Charitate (1668–1672). In 1657, he lent Vermeer 200 guilders.
Magdalena had 20 of Vermeer's works in her estate at her death, inherited from her father.
Magdalena van Ruijven died in 1682, one year after her mother. Her spouse inherited most of her wealth, including 20 paintings by Vermeer. In 1683, the estate was divided by Dissius and his father. In 1694 Abraham Dissius was buried, his son Jacob died the year after.
On May 16, 1696, twenty-one paintings by Vermeer were sold in an auction in Amsterdam. These paintings brought a total of 1,503 guilders, about seventy guilders each. It is presumed the paintings had belonged to the Van Ruijvens, who had built up a large collection of paintings by Vermeer, three by Emanuel de Witte, four by Simon de Vlieger and one by Jan Porcellis.
- J.M. Montias (1989) Vermeer and his milieu, A web of social history, p. 254, 360.
- Catalogus of naamlyst van schilderyen, met derzelver prysen, zedert ... 1752. tot ... 1768. ... openbaar verkogt. : Dienende tot een vervolg ... op de ... cataloguen door Gerard Hoet .../ Uitgegeeven door Pieter Terwesten, 1770, p. 34-36; J.M. Montias (1989) Vermeer and his milieu. p. 363-364.
- Vermeer and The Delft School, a full text exhibition catalog from The Metropolitan Museum of Art, which contains material on Pieter van Ruijven