Mulroney is the elected MPP for the riding of York—Simcoe since her 2018 election, and was a candidate in the 2018 Ontario Progressive Conservative Party leadership election, placing third. She served as Attorney General of Ontario from 2018 to 2019.

Mulroney is the only daughter and the oldest child of the 18th Prime Minister of Canada, Brian Mulroney, and his wife, Mila Mulroney. Mulroney was educated at Harvard University and New York University School of Law, and has extensive business, legal and charitable experience prior to her entry to politics. Mulroney is fluent in French, English, Spanish and Serbian, and also serves as the Minister of Francophone Affairs.