The Metropolitan King County Council, the legislative body of King County, Washington, consists of nine members elected by district. The Council adopts laws, sets policy, and holds final approval over the budget. Its current name and structure is the result of a merger of King County and the Municipality of Metropolitan Seattle, better known as Metro, which was a federated county-city structure responsible for water quality and public transportation.

As a result of a County Charter amendment passed by voters in the November 2008 elections, all elective offices of King County are officially nonpartisan; that being said, all current council members have made their party affiliations a matter of public record.^{[1][better source needed]}

• District 1: Rod Dembowski (D),^[1] took office 2013
• District 2: Girmay Zahilay (D),^[1] took office 2020
• District 3: Sarah Perry (D),^[2] took office 2022
• District 4: Jorge Barón (D), took office on January 9, 2024^[3]
• District 5: Dave Upthegrove (D),^[1] took office 2014
• District 6: Claudia Balducci (D),^[1] took office 2016
• District 7: Pete von Reichbauer (R),^[4] took office 1994
• District 8: Teresa Mosqueda (D), took office on January 9, 2024^[3]
• District 9: Reagan Dunn (R),^[5][6] took office 2005

The full county council meets weekly on Thursdays, except for the fifth Thursday in a month. Public comments are permitted at the fourth meeting of the month. Meetings are held in the County Council chambers, Room 1001, on the tenth floor of the King County Courthouse in Downtown Seattle.^[7]

The nine members of the council are elected by their district to four-year terms in nonpartisan contests. Councilmembers in even numbered districts are up for election in 2023, while Councilmembers in odd districts are up for election in 2025.^[8] Prior to 2009, councilmembers were elected on a partisan basis, and had to declare their political party unless they filed as an Independent. An independent candidate had to receive at least 20 percent of the vote in the primary election to qualify for the general election ballot.^{[citation needed]} This changed upon the passage of Charter Amendment 8 by voters in 2008, which made all elections for county offices nonpartisan.^[9]

The Council uses its committee structure to consider the legislation before it. Ordinances and motions (policy statements) are assigned to a King County Council committee for consideration, and then are recommended to the full Council for action. Each year, the Council reorganizes and elects a Chair and Vice Chair. In addition, the Council decides yearly on its committee structure and makeup. Currently there are nine standing policy committees and three regional committees. Members of the Seattle City Council and representatives from suburban cities and local sewer districts are also members of the regional committees. In addition, all nine members of the Council meet as a Committee of the Whole to discuss broad-reaching legislation and issues.

The King County Executive is not a member of the Council, and is a separately elected official. The Executive submits legislation to the Council for consideration. Each year in October, the Executive submits a proposed budget to the County Council for the operation of County government for the coming year. The Executive has veto power over ordinances passed by the Council.

In the 2004 general election voters approved a charter amendment to reduce the size of the council from thirteen to nine, which went into effect January 1, 2006. With four fewer districts, the number of constituents per district rose from 138,000 residents to about 193,000.^[10]

As of 2017^[11]