Isidoor Teirlinck (Zegelsem, 2 January 1851 - Forest, Brussels, 27 June 1934) was a Belgian writer. He is best known for his work on folklore.
Isidoor Teirlinck went to school in Lier. He married with Oda van Nieuwenhove and he was the father of the writer Herman Teirlinck. He became a teacher and taught in Serskamp, Drogenbos, Saint-Josse-ten-Noode, and from 1875 onwards, he was teacher in mathematics and physics in Brussels. He wrote several books, together with his brother-in-law Reimond Stijns, as Teirlinck-Stijns. Their most famous novel was Arm Vlaanderen (E: Poor Flanders), which they published in 1884.