Payette has served on boards of directors, at Queen's University, Canada's Own the Podium Olympic program, Montreal Science Centre foundation, Robotique FIRST Québec, Drug Free Kids Canada, the Montreal Bach Festival, the National Bank of Canada, Développement Aéroport Saint-Hubert de Longueuil, and others. In about 2017, she was appointed to the International Olympic Committee's Women in Sports Commission. She is a member of the Ordre des ingénieurs du Québec and a fellow of the International Academy of Astronautics. As well, Payette is a member of the Faculty of Engineering Advisory Board of McGill University.
Payette was announced on July 13, 2017, as Prime Minister Justin Trudeau's recommendation to be the 29th Governor General of Canada. She was scheduled to take office October 2, 2017, after the completion of briefings from the incumbent, David Johnston. After the announcement was made, Johnston issued a statement congratulating Payette and welcoming "a Canadian of extraordinary achievement, admired by all".
As governor general-designate, Payette had her first official meeting with Queen Elizabeth II on September 20, 2017, at Balmoral Castle, when she was also invested by Her Majesty as an extraordinary Companion of the Order of Canada (CC), an extraordinary Commander of the Order of Military Merit (CMM), and a Commander of the Order of Merit of the Police Forces (COM).
Payette was installed as governor general on October 2, 2017. Afterwards, she urged Canadians to work together on issues such as climate change, migration and poverty. "Anyone can accomplish anything and rise to the challenge as long as they are willing to work with others, to let go of the personal agenda, to reach a higher goal and to do what is right for the common good. This is exactly what I hope my mandate as the governor-general will reflect", Payette said.