Leading Antitrust partner joins A&O Shearman in Washington, D.C.

Kathryn joins A&O Shearman with complex antitrust trial experience combined with deep sector specific expertise in life sciences, energy, chemicals, and technology—areas where industry-specific insight, regulatory fluency, and deep market understanding are critical to successfully engaging with regulators and protecting commercial objectives. Her experience across these areas further strengthens the firm’s ability to deliver practical and commercially focused counsel to clients facing increasing antitrust scrutiny.

“Kathryn’s combination of antitrust trial experience, specialized counseling, disputes expertise, and deep sector knowledge positions her to successfully advise clients as antitrust scrutiny and enforcement intensifies across industries. I’m delighted she is joining the team,” said Noah Brumfield, co-head of U.S. Antitrust at A&O Shearman.

“I’m excited to join A&O Shearman and work with a globally integrated Antitrust practice and teams around the world. The firm’s global platform and deep sector expertise create a powerful opportunity to help clients navigate complex, consequential antitrust challenges across jurisdictions,” said Kathryn Mims. 

Kathryn joins A&O Shearman from White & Case.

A&O Shearman recently welcomed Paul Astolfi (Energy, Natural Resources, and Infrastructure), Katy McNeil (Energy, Natural Resources, and Infrastructure), Michael Kim (Capital Markets), Ned Schodek (Restructuring), Jan Sysel (Fund Finance), Valentine Bleicher (Mergers and Acquisitions), Nick Ramphal (Mergers and Acquisitions), and Catherine Hein (International Trade and CFIUS) as partners in the U.S.

Globally, the firm has expanded core practice areas with 40 partner hires since the completion of the A&O Shearman merger on May 1, 2024.