The Washington State Democratic Party is the affiliate of the Democratic Party in the U.S. state of Washington, headquartered in Seattle. It is also commonly referred to as the Washington State Democrats and the Washington Democratic Party. It is currently the dominant party in the state, controlling the majority of Washington's U.S. House seats, both U.S. Senate seats, both houses of the state legislature, and the governorship.

The Washington State Legislature is the state legislature of the U.S. state of Washington. It is a bicameral body, composed of the lower Washington House of Representatives, composed of 98 Representatives, and the upper Washington State Senate, with 49 Senators plus the Lieutenant Governor acting as president. The state is divided into 49 legislative districts, each of which elect one senator and two representatives.