Tassilo, Baron von Heydebrand und der Lasa (known in English as "Baron von der Lasa", 17 October 1818, Berlin – 27 July 1899, Storchnest near Lissa, Greater Poland, then German Empire) was an important German chess master, chess historian and theoretician of the nineteenth century, a member of the Berlin Chess Club and a founder of the Berlin Chess School (the Berlin Pleiades).