The 43rd meeting of Canadian Mathematics Education Study Group (CMESG) was held at St. Francis Xavier University in Antigonish, Nova Scotia (May 31-June 4, 2019). This meeting marked only the third time CMESG/GCEDM (Groupe Canadien d'Étude en Didactique des Mathématiques) had been held in Nova Scotia (1996, 2003), and the first time it had been held at St. Francis Xavier University. The meeting was attended by 116 participants, 25 of which were first timers. The meeting featured a scientific program organized into six working groups, four topic sessions, five new PhD presentations, 18 gallery walk presentations, and 12 AdHoc sessions. Twenty-six papers are included in these proceedings--two are written in French, eight are provided in both French and English, and the remainder are written in English. [For the 2018 proceedings, see ED595075.]