Theodoor van Loon (1581 or 1582, in Erkelenz – 1649, in Maastricht) was a Flemish Baroque painter.
Together with Wenzel Coebergher he completed commissions for Albert VII, Archduke of Austria and his wife Infanta Isabella Clara Eugenia of Spain.
He also completed commissions for churches in the region of Brussels, and made an altarpiece for the Basilica of Our Lady of Scherpenheuvel (Mariataferelen, 1623–28).
He was friends with Erycius Puteanus, a professor from the University of Leuven.
According to Houbraken, his paintings show that he spent his training in Italy.