Nancy J. King is an American politician who is a member of the Maryland Senate from the 39th district since 2007. A member of the Democratic Party, she has served as the majority leader of the Maryland Senate since 2020. King previously represented the district in the Maryland House of Delegates from 2003 to 2007.

The Maryland Senate, sometimes referred to as the Maryland State Senate, is the upper house of the General Assembly, the state legislature of the U.S. state of Maryland. Composed of 47 senators elected from an equal number of constituent single-member districts, the Senate is responsible, along with the Maryland House of Delegates, for passage of laws in Maryland, and for confirming executive appointments made by the Governor of Maryland.