CHEVY CHASE, MD, January 07, 2026 /24-7PressRelease/ -- Ian Simmons has been included in Marquis Who's Who. As in all Marquis Who's Who biographical volumes, individuals profiled are selected on the basis of current reference value. Factors such as position, noteworthy accomplishments, visibility, and prominence in a field are all taken into account during the selection process.

Mr. Simmons has established a distinguished career in antitrust and competition law, currently serving as a partner and former co-chair of the antitrust and competition practice at O'Melveny & Myers LLP in Washington, DC, since 1998. With over two decades at the firm, he has become recognized as an expert in antitrust and federal and state court litigation. Mr. Simmons' tenure is marked by his leadership in cases of first impression, including serving as lead counsel in four landmark antitrust matters.

Among his most notable achievements, Mr. Simmons served as counsel to Nippon Paper in the first criminal price-fixing jury trial in Boston in 1998. This case was historically significant as the first criminal trial involving a wholly foreign price-fixing conspiracy, with allegations that Japanese fax paper manufacturers conspired in Tokyo to fix the prices of fax paper shipped to the United States. The case set a precedent when the court required proof that the alleged conspiracy had a substantial effect on United States commerce. The jury was deadlocked on this issue, leading to a dismissal documented in a published opinion.

Mr. Simmons also served as lead counsel in the first antitrust case involving Bitcoin and cryptocurrency, which he successfully had dismissed. He played a pivotal role on the trial team in the first jury trial of a two-sided market case on behalf of American Airlines and US Airways against Sabre in 2022. Additionally, he led the first appeal on a significant preemption issue under the Federal Aviation Act, addressing whether state antitrust laws are preempted and whether state claimants can sue foreign air carriers. Mr. Simmons prevailed in the Ninth Circuit, which became the first court to rule on this matter.

Prior to his current role, Mr. Simmons served as counsel to the Permanent Subcommittee on Investigations for the Committee on Governmental Affairs of the United States Senate from 1997 to 1998. In this capacity, he contributed to high-level governmental investigations and policy development.

From 1994 to 1997, Mr. Simmons represented the United States as a trial attorney in the Antitrust Division, Computers and Finance Section at the United States Department of Justice in Washington, DC, where he held top secret clearance. During this period, he was honored to meet Janet Reno, the first woman Attorney General, and Ann Bingaman, the first woman Assistant Attorney General — an experience that left a lasting impression on him as a naturalized citizen.

Earlier in his career, Mr. Simmons served as a special assistant at the Office of the United States Attorney for the Eastern District of Virginia from 1996 to 1997, where he gained valuable prosecutorial experience. He began his legal career clerking for The Honorable Gustave Diamond, chief judge of the United States District Court for the Western District of Pennsylvania from 1991 to 1992.

In addition to his legal practice, Mr. Simmons has contributed to legal education as a senior lecturing fellow at Duke University Law School since 2020. He has also served as an associate editor for ABA Antitrust Magazine since 2010.

Mr. Simmons' professional excellence has been recognized through numerous awards that highlight his leadership and expertise in antitrust and competition law. He has been named by Who's Who Legal for Litigation and as a Thought Leader in Competition, received the Litigation of the Month Award in 2025, and earned the Outstanding Performance Award from the American Bar Association in 2023 and 2024. His department was recognized by the National Law Journal as the DC Litigation Department of the Year for General Litigation in 2019, and Benchmark Litigation named him a National Practice Area Star in Antitrust and Competition.

Additionally, Mr. Simmons has received several individual honors, including being named a Best Lawyer in America for Antitrust Law, a Top Lawyer for Antitrust by Chambers USA, an Antitrust Trailblazer by the National Law Journal and an MVP of the Year for Competition Practice by Law360. Between 2008 and 2018, he was repeatedly recognized as a Recommended Lawyer in Antitrust by The Legal 500. These accolades reflect Mr. Simmons' sustained excellence and impact in the field.

Mr. Simmons is an active member of the Antitrust Section of the American Bar Association and has made significant contributions to thought leadership in his field. He has authored several influential publications, including "Necessity as the Mother of Invention? Streamlining the Evaluation of Competitor Collaborations," published by the ABA Antitrust Law Section in 2020, as well as "ABA Section of Antitrust Law: Updates from Asia" and "The EC Communication on SEPs: Convergence, Divergence, or Silence?," both published in 2018.

At the outset of his professional journey, Mr. Simmons earned a Bachelor of Arts in political science from McGill University in Montreal in 1986, followed by a Master of Arts in political science from Yale University in New Haven in 1988. He went on to earn a Juris Doctor from the University of Pennsylvania Carey Law School in Philadelphia in 1991.

Born in Toronto, Mr. Simmons immigrated to the United States and built his career from the ground up, without prior contacts or networks. He attributes his success to his enthusiasm and passion for law, a drive shaped by growing up as the youngest sibling, striving to prove himself and inspired by a deep admiration for the opportunities in his adopted country. He places great value on mentoring younger colleagues and believes that shared values are essential for progress.

Outside his professional commitments, Mr. Simmons enjoys playing soccer. Looking ahead, he remains deeply committed to advancing American antitrust law while mentoring the next generation of leaders, helping shape the future of the field with the same passion and dedication that have defined his career.

About Marquis Who's Who®:
Since 1899, when A. N. Marquis printed the First Edition of Who's Who in America®, Marquis Who's Who® has chronicled the lives of the most accomplished individuals and innovators from every significant field of endeavor, including politics, business, medicine, law, education, art, religion and entertainment. Who's Who in America® remains an essential biographical source for thousands of researchers, journalists, librarians and executive search firms around the world. The suite of Marquis® publications can be viewed at the official Marquis Who's Who® website, www.marquiswhoswho.com.

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