Joost Cornelisz Droochsloot or Droogsloot was a Dutch Golden Age painter.

According to Houbraken his village scenes (Boerekermisstuk) were as popular as flower pieces by Bartholomeus Assteyn. Houbraken thought he was born in Gorinchem or Dordrecht, and claimed he worked for a long time in Dordrecht. He felt his work was always according to a set pattern, where cake sellers were portrayed in front of village houses with figures in a festive setting called a "farmer's circus". It is unclear why Houbraken would have thought he was from Dordrecht, especially since Houbraken's data on painters from Dordrecht was generally quite accurate. Droochsloot and his son were highly respected citizens of Utrecht with a large workshop.

According to the RKD his monogram was "JCODS" and he became a member of the Utrecht Guild of Saint Luke in 1616. He later became deacon of the guild in 1623 and regent of the St. Jobs Gasthuis in 1638, deacon of the Dutch Reformed church, and in 1665 officer of the Utrecht schutterij.He was the father of the painter Cornelis Droochsloot (1630-1673) whose paintings are hard to distinguish from his own, and the teacher of Jacob Duck.