Willem van Heythuysen (1590s – 1650), was a Dutch cloth merchant and hofje founder in Haarlem and Weert.

He is best known today for his portraits by Frans Hals, though he is remembered locally for his Hofje van Willem Heythuijsen bordering Haarlemmerhout park, which has been in operation for centuries.

His neighbor there on the grounds of Spaar en Hout, was Zacharias Hooftman, an Amsterdam merchant who lived in the winter on the Herengracht.

He appointed his brother Frans van Heythuysen and Tieleman Roosterman to build the hofje in Weert.

[4] It was sold by the hofje regents in 1869 by public auction in Paris and was acquired the following year by the Royal Museums of Fine Arts of Belgium in Brussels.

In recent years a modern apartment complex called Middelhout has been built on a corner of the old grounds of Sparenhout.

Willem van Heythuysen was buried in the St. Bavochurch in Haarlem, where his gravestone can still be seen on the south side of the choir.