Kathleen M. "Katie" O'Sullivan

Seattle, WA Directions

Recognized in Best Lawyers since 2009

Awarded Practice Areas

Appellate Practice Bet-the-Company Litigation Commercial Litigation

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Works at

Ashurst Perkins Coie

243 Best Lawyers awards

Biography

Kathleen M. O'Sullivan is a lawyer recognized by Best Lawyers in the practice areas of Appellate Practice, Bet-the-Company Litigation and Commercial Litigation. Kathleen M. practices law in Seattle, Washington

Best Lawyers has recognized Kathleen M. O'Sullivan since 2009. The Best Lawyers recognition is based on a peer-review survey of lawyers in the same geographic region and legal practice area. The recognition reflects the professional regard in which Kathleen M. O'Sullivan is held by other lawyers.

Locations

Seattle, Washington

206-359-8000

1301 Second Avenue Suite 4200
Seattle, WA 98101-3804

Education

Georgetown University, J.D., graduated 1996
Yale University, BA

Bar Admissions

Washington, Washington State Bar Association

Affiliations

American Law Institute - Member
Federal Bar Association - Member
Washington State Bar Association - Member

Federal Clerkships

United States Court of Appeals
United States District Court

Client Testimonials

Awards & Focus

Named "Lawyer of the Year" by Best Lawyers^® for:

Appellate Practice, Seattle (2026)
Bet-the-Company Litigation, Seattle (2025)
Appellate Practice, Seattle (2024)
Appellate Practice, Seattle (2016)

Recognized in The Best Lawyers in America^® 2027 for work in:

Appellate Practice
Bet-the-Company Litigation
Commercial Litigation

Special Focus:

Appellate
Civil Litigation
Class Actions
Complex Litigation

Awards:

Co-Recipient of awards for IOLTA Supreme Court litigation (American Bar Association, Washington State Bar Association, King County Bar Association, Perkins Coie)
Listed in Washington Law & Politics, “Washington's Super Lawyers," 2007 - Present

News & Media

Case History

Cases

Other Court Admissions

U.S. Supreme Court
U.S. Court of Appeals for the Ninth Circuit
U.S. District Court for the Western District of Washington
U.S. District Court for the Eastern District of Washington

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