The Washington State Democratic Party is the affiliate of the Democratic Party in the U.S. state of Washington, headquartered in Seattle.

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.

In addition, the State Central Committee has one representative from each of Washington's 10 Congressional Districts, six at-large members, and four DNC members.

The final two members are a representative from the Young Democrats of Washington and the President of the Washington Federation of Democratic Women.

Each of Washington's 49 legislative districts has a local Democratic party organization, which operates within that district and sends two delegates (which may not share the same gender identity) to the State Central Committee.