Kathleen O'Day Wynne is a former Canadian politician who served as the 25th premier of Ontario and leader of the Ontario Liberal Party from 2013 to 2018. She was member of provincial parliament (MPP) for Don Valley West from 2003 to 2022. Wynne is the first female premier of Ontario and the first openly gay premier in Canada.

The premier of Ontario is the head of government of Ontario. Under the Westminster system, the premier governs with the confidence of a majority the elected Legislative Assembly; as such, the premier typically sits as a member of Provincial Parliament (MPP) and leads the largest party or a coalition of parties. As first minister, the premier selects ministers to form the Executive Council, and serves as its chair. Constitutionally, the Crown exercises executive power on the advice of the Executive Council, which is collectively responsible to the legislature.