The meeting is taking place at the Potocki Palace in Lviv, an Ukrinform correspondent reports.
Earlier, the presidential press service reported that during the talks the sides would discuss further deepening of special partnership between Ukraine and Canada, in particular, in the field of security.
Poroshenko and Payette also plan to visit the International Peacekeeping and Security Center, where Ukrainian servicemen are trained as part of Canada's UNIFIER mission.
Payette will then leave Ukraine for Latvia, where about 1,000 Canadian military serve.
Payette was appointed Governor General of Canada in October last year. A visit to Ukraine and Latvia will be her first trip abroad as commander-in-chief of the Canadian Armed Forces. The governor general of Canada last visited Ukraine in 2009.