Barend Graat was a Dutch painter of history- and altarpieces, landscapes and portraits in the Golden Age. He is also known as a printmaker and draughtsman.

Barend Graat was baptized in the Nieuwe Kerk (Amsterdam). According to Houbraken, who only saw his etchings, Graat learned to paint from his uncle Hans. Though he never traveled to Italy, he became proficient in making small Italianate landscapes and genre pieces in the manner of Pieter van Laer. He signed his works B. Graat fecit. Graat was known for his skill painting farm animals, and taught the painter Johann Heinrich Roos, whom he outlived.

Graat had connections with Jan Vos, a poet and playwright. In 1660 he married a young widow and decided not to travel to Italy, although he had made preparations. In 1664 he bought a plot and had a house build on Leidsegracht In 1668 and 1670 two daughters were baptized in a hidden Catholic church. In 1672 he was one of the painters evaluating a collection of paintings sold by Gerrit Uylenburgh to pronounce their authenticity. For fifteen years, the painter led an art academy at his house.