Frans Mostaert (1528, Hulst – 1560, Antwerp) was a Dutch Renaissance painter.
According to Karel van Mander he was the son of a common painter, the twin brother of the painter Gillis Mostaert and the grandson of the painter Jan Mostaert.[1] Gillis looked so much like him that their own father couldn't tell them apart.[1] Both brothers joined the Antwerp Guild of St. Luke in 1555.[1] While his brother Gillis studied landscape painting in Haarlem from Jan Mandijn, Frans became a pupil of Herri met de Bles and later became an inspiration for Jan Soens, who worked for a period in Gillis Mostaert's workshop in Antwerp before leaving for Parma, Italy.[1]
Frans died of the plague after his new pupil Bartholomeus Spranger had been with him for a few weeks.[1] Few of his works survive, though he had been a respectable landscape painter before his death.