Sean O'Donnell, a King County Superior Court judge, is running for Washington State Supreme Court Justice Position 4 in the Nov. 3, 2026, general election. The nonpartisan race also includes Ian Birk.
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
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."
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."
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 also described his prosecutorial career in the questionnaire: "I 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. 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."
Asked about accomplishments, 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: "I am also proud of helping King County bring needed focus to how it runs its protection order court. 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."
O'Donnell also pointed to leadership roles, saying he has helped lead efforts to "improve courthouse security, fund court interpreters, reform pretrial practices, and guide judges through A.I.'s impact on justice."
According to BallotReady, O'Donnell worked as a communications manager at The Boeing Company from 1997 to 2000 before entering law. He has served as a board member at Lakeside School since 2017.
On the issues
O'Donnell cited experience and public safety as key differences with his opponent. The following excerpts are from a longer answer 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. My opponent has none in criminal justice."
Best advice: O'Donnell said 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.'"
