Tobias S. Loss-Eaton

TOBIAS LOSS-EATON is an appellate and regulatory litigator who helps clients navigate complex, novel, or high-stakes legal issues, from the earliest strategy discussions to the U.S. Supreme Court. Chambers USA, which has ranked him for Transport: Rail (for Railroads) in USA—Nationwide (2023–2025), notes his “impressive experience,” with clients reporting that he is “a fantastic lawyer” and “an excellent civil litigation advocate” who “provides great client service.” One client tells Chambers: “Tobias is my first call when there is no playbook for complex issues. He approaches issues with calm, reasoned discernment. His judgment, intellect and writing abilities are top-rate.”

As a member of Sidley’s Supreme Court & Appellate and Regulatory Litigation practices, Tobias has extensive experience challenging and defending state and federal agency actions and regulations, including in the environmental, trade, securities, and healthcare sectors. That experience includes addressing the key threshold questions of when, where, and how to press an issue in the proper judicial forum—including issues of personal jurisdiction, sovereign immunity, federal removal jurisdiction, and abstention. It also includes substantial experience with federal preemption and Takings Clause issues. Tobias also has significant experience in complex contractual and commercial disputes, including cases involving the Federal Arbitration Act and insurance and reinsurance issues.

Tobias is also part of Sidley’s top-ranked Transportation group. Chambers USA highlights his strong experience advising and litigating on behalf of the nation’s largest freight railroads (2023–2025). He has represented the railroads in many cases involving federal preemption or preclusion, contractual disputes, challenges to regulatory action, and the proper interpretation of the Federal Employers Liability Act (FELA). He also advises and litigates on behalf of airline-industry clients on preemption, regulatory, and commercial issues. So far in 2025, Tobias and the Transportation team have won three precedent-setting appeals, in the Fourth and Seventh Circuits and the Virginia Supreme Court.

Tobias prides himself on clearly explaining complex legal issues to busy generalist judges. One prominent legal writing expert has praised Tobias’s briefs as better than the typical work product of “elite” Supreme Court advocates. Tobias has written or coauthored over 185 briefs in state and federal appellate courts, including over 90 briefs in the Supreme Court. He has presented oral argument in the Second, Fourth, Sixth, Seventh, and D.C. Circuits and in state appellate and supreme courts, producing successful results for his clients in 70% of the appeals he has argued.

Tobias is a co-director of the Carter G. Phillips/Sidley Austin LLP Supreme Court Clinic at Northwestern Pritzker School of Law, where he teaches Supreme Court advocacy, moots advocates preparing for merits arguments, and supervises students working with Sidley lawyers on cases at the Court.