The 11th biannual symposium Quantum Theory and Symmetry was organized by Richard MacKenzie and Manu Paranjape of the GPP, along with  Yvan Saint-Aubin, Alfred Shapere, Luc Vinet and William Witczak-Krempa rounding out the local organizing committee.  The meeting was held from July 1st to July 5th, 2019, and hosted at the Centre de recherche mathématiques, Université de Montréal.