Gerard van Deynen (fl 1665 – after 1673), was a Dutch painter, who was enrolled in the Guild of Saint Luke of The Hague from 1665 to 1673. He was possibly the father or brother of Isaac van Duynen, a still life painter.
He is sometimes confused with a 'G. van Deynum' or 'Guilliam van Deynum', a still life painter who worked in Antwerp.