Mary Lynn Washington is an American politician who has served as a member of the Maryland Senate from District 43 since 2019. She previously represented the district in the Maryland House of Delegates from 2011 to 2019.

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.