Jack Millman

Jack Millman has distinguished himself as a leading appellate and trial litigator. A former law clerk to U.S. Supreme Court Justice Clarence Thomas, and previously to Judge Diarmuid F. O’Scannlain of the Ninth Circuit and Judge Edward Earl Carnes of the Eleventh Circuit, Jack brings appellate insight from the highest levels of the federal judiciary to every matter he handles.

Jack played a major role on an HSG team that secured a unanimous victory at the U.S. Supreme Court in a case against Halliburton Energy Services. That victory resolved a circuit split over when federal courts can reopen voluntarily dismissed lawsuits. The firm’s merits brief garnered widespread acclaim among appellate practitioners.

He has also argued before the Sixth and Seventh Circuits, and his successes have been recognized in Law360’s Legal Lions and The American Lawyer’s Litigator of the Week columns.

His practice spans high-stakes commercial litigation at both the trial and appellate levels across federal and state courts throughout the country. In 2025, Jack helped secure a reversal at the Ninth Circuit that reinstated in full an $81 million trade secrets jury verdict in favor of an aerospace startup against Boeing. Jack served as the lead associate, drafting the Ninth Circuit opening and reply briefs. The appellate panel unanimously reversed the district court and reinstated the jury verdict in full.

In another Ninth Circuit victory, Jack helped win affirmance of a summary judgment ruling in favor of battery-material leader Nexeon Ltd., which had been accused of violating federal and state trade secret laws and a non-disclosure agreement related to lithium-battery technology.

At the trial level, Jack is part of the HSG team representing a major insurer in coverage litigation over sex-abuse claims, with hundreds of millions of dollars at stake. He also represents H.I.G. Capital in litigation asserting fraud claims connected to the $900 million sale of a portfolio company.

A former Ohio certified public accountant as well as a lawyer, Jack has particular depth in financial disputes, including securing a $69.8 million recovery against a prominent hedge fund owner.

Jack is also an active pro bono practitioner. In an appeal argued before the Sixth Circuit, he secured a ruling vacating his client’s criminal sentence of nearly five years because the guilty plea was not knowing and voluntary.

Jack is an adjunct professor at New York University School of Law and co-teaches the Supreme Court Simulation Seminar with Dean Troy McKenzie.

Before entering private practice, Jack served as a captain in the New York and Ohio Army National Guards from 2006 to 2019 and received a Bronze Star Medal for meritorious service in Afghanistan in 2012. He was previously an associate at Jones Day and at Wachtell, Lipton, Rosen & Katz.