Pieter de Neyn, or Deneyn (December 1597 – 16 March 1639) was a Dutch Golden Age painter.

According to Houbraken Deneyn's father apprenticed him to a mason, where he stayed a few years but decided to study further, specifically the fields of mathematics and architecture.

His parents could not pay for a proper education, and he became good enough at masonry that he began to teach others.

He died of lung disease, which Houbraken claims was common among masons.

[1] According to the Netherlands Institute for Art History (RKD), he painted landscapes and battle scenes, and was a pupil from 1611 to 1617 of Esaias van de Velde in Haarlem during the same period as Jan van Goyen, who also influenced his work.