Isaac Jansz van Ostade (Haarlem, 1621 – Haarlem, 1649) was a Dutch painter, draughtsman and print artist from North-Holland. He was the younger brother of Adriaen van Ostade, who was also his teacher. He spent his entire career working in Haarlem, where he became a member of the Guild of Saint Luke in 1643.

In his short life – he was only 28 years old when he died – Isaac van Ostade produced (what is currently known to be) about a hundred paintings. His work consisted mainly of various landscapes and the peasant genre, but it was his winter landscapes or ice scenes that he was best known for. Isaac van Ostade is also known for repeatedly placing certain buildings or figures, such as the white horse with a sledge, in his paintings.