The siege of Grol or Groenlo in 1595 was a siege of Groenlo by States forces under Maurice of Nassau during the Eighty Years' War in an attempt to capture it from the Spanish Empire. It lasted from 14 to 24 July 1595, ending with the arrival of a Spanish relief force under Cristóbal de Mondragón and Maurice's retreat. Two years later, in 1597, Maurice returned to carry out another siege of Groenlo. Both these sieges formed part of what would later be called the Ten Glorious Years.