Kathleen M. "Katie" O'Sullivan

4.6 (39 reviews )

Seattle Washington United States

Appellate Practice Bet-the-Company Litigation Commercial Litigation

Recognized in Best Attorney USA since 2009

206-359-8000 Website

About Kathleen

Kathleen M. O'Sullivan is a top attorney recognized by Best Lawyers in the practice area(s) of Appellate Practice, Bet-the-Company Litigation and Commercial Litigation.Kathleen M., who practices law in Seattle, Washington, has been recognized since 2009. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Kathleen M. is held by other top lawyers in the same geographic and legal practice area.

Kathleen M. O'Sullivan is a top attorney recognized by Best Lawyers in the practice area(s) of Appellate Practice, Bet-the-Company Litigation and Commercial Litigation.

Kathleen M., who practices law in Seattle, Washington, has been recognized since 2009. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Kathleen M. is held by other top lawyers in the same geographic and legal practice area.

Practice Areas

Appellate Practice

Bet-the-Company Litigation

Commercial Litigation

Case History

Education

Georgetown University

Yale University

Professional Affiliations

Awards & Recognition

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Reviews

4.6 / 5

39 Reviews

1,049 Profile Views

Raymond Mayer

Jan 31, 2026

Five stars for the incredible team at Kathleen M. "Katie" O'Sullivan in Seattle - they are amazing

Best lawyer for Appellate Practice law in Seattle. Period. I've seen others, but Kathleen M. "Katie" O'Sullivan is on another level. They truly care about their clients and work hard to get the best r...

Tim Rath

Jan 31, 2026

Top notch experts in Seattle - Kathleen M. "Katie" O'Sullivan is by far the best lawyer I've ever had

Really glad I found Kathleen M. "Katie" O'Sullivan for my case. They were a huge help and made everything understandable. I was very impressed with their knowledge and how they handled the opposition....

Annette Lubowitz

Jan 31, 2026

Great people who truly care at Kathleen M. "Katie" O'Sullivan - the best legal team in Washington

Kathleen M. "Katie" O'Sullivan has been doing this since Recognized in Best Lawyers since 2009, and it definitely shows in their work. They're pros through and through and I wouldn't trust anyone else...

Danielle Hyatt

Jan 31, 2026

Excellent legal representation provided by Kathleen M. "Katie" O'Sullivan for my Appellate Practice law case

Super helpful and professional staff at Kathleen M. "Katie" O'Sullivan's office. Thanks again for everything you did for me! It was a long journey, but you made it much easier with your constant suppo...

Glenn Thompson

Jan 31, 2026

Top notch experts in Seattle - Kathleen M. "Katie" O'Sullivan is by far the best lawyer I've ever had

Kathleen M. "Katie" O'Sullivan is fantastic and very professional. Don't hesitate to hire them if you're in Washington and need help. They really know their stuff and will go the extra mile to make su...

Kathleen M. "Katie" O'Sullivan

About Kathleen