David Jonathan Heyman (born 26 July 1961) is a British film producer and the founder of Heyday Films. Heyman is best known as the producer of all eight instalments of the Harry Potter film series, which are based on a series of popular fantasy novels of the same name by author J. K. Rowling. He then produced all three instalments of its spin-off prequel series, Fantastic Beasts. His work makes him the second-most commercially successful producer of all time.David Heyman, licensed under CC-BY-SA, full list of contributors on Wikipedia.