King County Superior Court Judge Sean O'Donnell is running for Washington State Supreme Court Justice, Position 4, in the Nov. 3, 2026, general election. The nonpartisan race is one of five Supreme Court seats on the ballot. Ian Birk is the other candidate certified for the race, according to BallotReady election data.
Asked why he is seeking the seat, O'Donnell said in our candidate questionnaire: "I'm running for the Washington State Supreme Court because I love being a judge and I think I can make a difference for our State and its system of justice. I have been a public servant for 25 years, as a prosecutor and judge."
Candidate information
Education: O'Donnell said in our questionnaire: "After growing up in the Seattle area, I earned my undergraduate degree from Georgetown University in 1994. I then earned my JD cum laude from Seattle University School of Law in 2001."
Family: O'Donnell said in our questionnaire: "My wife and I have been married for over 20 years and have two young-adult children. My wife is a small-business owner in Seattle. She is a pediatric occupational therapist who helps kids with disabilities and has a specialty focus in autism."
Party affiliation: O'Donnell said in our questionnaire: "I am running for a nonpartisan position. Under the Judicial Code of Conduct, judges do not share their party affiliation. I am a recommended candidate by both of the state's major political parties. Among all of the candidates running for all of the seats in this race, I am alone in that distinction."
Experience and public service
O'Donnell described his career in our questionnaire: "I am a King County Superior Court Judge. For 13 years I have presided over complex criminal, civil, and family law cases. Today my courtroom is at Harborview Medical Center, where I am lead judge for the Involuntary Treatment Act mental health court."
He said he "started in Attorney General Gregoire's office, then spent 12 years as a King County Prosecutor handling serious felonies, including homicides and child sexual assaults." O'Donnell added: "I helped prosecute the Green River Killer and tried the state's first human trafficking case. I have served as a pro tem Justice on the State Supreme Court."
On his leadership roles, O'Donnell said in our questionnaire: "For the past 13 years, I have served as an elected King County Superior Court Judge. I was named President of the Superior Court Judges' Association, Chief Family Law Judge, Chief Criminal Judge, and Special Inquiry Judge for King County."
Before law school, O'Donnell worked as a communications manager at The Boeing Company from 1997 to 2000, according to BallotReady.
On the issues
Accomplishments: Asked what past accomplishments show he can handle the job, O'Donnell said in our questionnaire: "I am proud of my work as a prosecutor on the Green River case, where our team resolved 49 open homicide cases and held one of America's most prolific serial killers responsible for his terrible crimes."
He also cited his work on protection orders: "That effort, and a legal decision I made upholding an important statute, have led to hundreds, if not thousands, of firearms being surrendered by people legally prohibited from having them."
Differences from opponent: O'Donnell drew several distinctions in our questionnaire. On experience, he said: "I have been a judge a decade longer than my opponent. I have made thousands of decisions affecting people's lives, held leadership roles in the judicial branch on budgeting, legislation and systems reform, and served as a pro tem justice on the State Supreme Court."
On public safety, he said: "I spent half my career giving crime victims a voice. Among all candidates and current justices, I have the most public safety experience."
Best advice: O'Donnell shared in our questionnaire: "The best advice I ever got about being a judge was this: 'treat every decision like it is the most important one in the world to the person standing in front of you – because it probably is.'"
