Margaret Norrie McCain is a Canadian philanthropist who was the first woman to serve as the lieutenant governor of New Brunswick.

The lieutenant governor of New Brunswick is the representative in New Brunswick of the monarch, who operates distinctly within the province but is also shared equally with the ten other jurisdictions of Canada, as well as the other Commonwealth realms and any subdivisions thereof, and resides predominantly in his oldest realm, the United Kingdom. The lieutenant governor of New Brunswick is appointed in the same manner as the other provincial viceroys in Canada and is similarly tasked with carrying out most of the monarch's constitutional and ceremonial duties. The current lieutenant governor is Brenda Murphy, since September 8, 2019.