Claire O’Brien

Claire O’Brien is a commercial litigator with significant trial, appellate, and arbitration experience across federal and state courts and arbitral forums. She represents blue-chip and startup companies, financial institutions, asset managers, boards of directors and public-sector clients in complex, high-stakes disputes. Claire has successfully represented plaintiffs and defendants in a broad array of litigations involving fraud, fiduciary duties, contractual breaches, indemnification, bankruptcy and distressed situations, defamation, business tort, and constitutional claims.

Claire also represents the New York Governor and executive agencies and their commissioners in high-profile commercial and regulatory disputes concerning consumer harms, antitrust, healthcare, opioids, social media, and constitutional and statutory issues. Claire’s clients span a multitude of industries and sectors, including insurance, pharmaceuticals, hedge funds and private equity, technology, digital assets, transportation, and natural resources. She is an experienced strategist who regularly oversees cases with multi-pronged issues and taking place across numerous venues and jurisdictions.

Claire also maintains an active public policy and impact practice focused on trial and appellate advocacy. Her pro bono docket has included criminal appeals, trial court proceedings, and amicus advocacy before the U.S. Supreme Court.

Her accomplishments have been acknowledged by several prominent publications, including Benchmark Litigation, which included her in their 2026 “40 & Under” list, the New York Law Journal, naming her to its exclusive “Rising Stars” list in 2025, and by Best Lawyers, listing her on its 2026 and 2027 “Ones to Watch” list in the commercial litigation category.

Claire’s complex commercial, trial, arbitration, and appellate representations include:

• A technology-focused venture capital firm and its founders in a long-running arbitration against a group of former passive investors challenging a management-buyout transaction. The investors asserted claims for breach of contract, breach of fiduciary duty, and unjust enrichment. After a week-long hearing in February 2024, the arbitration panel denied the investors’ claims in their entirety and ordered the investors to pay the defendants’ share of the arbitration costs, plus reasonable attorneys’ fees and expenses.
• A resource and technology-based company, in action brought by a bankruptcy estate, defending against breach of contract, breach of fiduciary duty, and fraud claims in a three-week arbitration hearing.
• Assured Investment Management and several of its managed funds in a Chapter 15 adversary proceeding in Bankruptcy Court for the Southern District of New York arising from the International Investment Group fraud, involving fraudulent transfer and aiding and abetting fraud and breach of fiduciary duty claims brought under New York and Cayman Islands law.
• New York Governor Kathy Hochul and executive state agencies and their commissioners, in a variety of matters involving complex state and federal constitutional and statutory issues.  This includes three separate state and federal enforcement actions brought by the New York Attorney General on consumer harm and antitrust against major social media companies. These cases have resulted in a series of rulings favorable to the Governor, including a successful Ninth Circuit mandamus petition and related trial-court victories preserving New York's separation of powers and limiting sweeping statewide discovery demands.
• Directors, officers, and shareholders of Kabbage, an online financial technology company, and one of the largest Paycheck Protection Program lenders during COVID-19, against claims of intentional and constructive fraudulent transfers and breaches of fiduciary duties. The dispute stems from the directors’ and officers’ alleged breaches of fiduciary duty, Kabbage’s participation in the Paycheck Protection Program, and from a “spin-out” merger entered into in connection with Kabbage’s $700 million sale of its fintech business to American Express, allegedly leaving the post-merger entity insolvent and/or undercapitalized. The disputes include the Delaware bankruptcy adversary proceeding, a DOJ False Claims Act allegations pending in Eastern District of Texas against the directors, and a Delaware Court of Chancery indemnification lawsuit with American Express.
• Bausch Health, a multinational pharmaceutical company, and one of its subsidiaries, Salix Pharmaceuticals, Ltd. in a lawsuit brought in the Delaware Court of Chancery, by Salix’s former CEO, in connection with the termination of the former CEO’s unvested equity-based awards. The case settled on the courthouse steps immediately prior to the first witness taking the stand at trial.
• Archer Aviation Inc., an aircraft manufacturing company, against The Boeing Company in a California state court lawsuit that sought up to $1 billion in damages caused by defamatory statements made by Wisk Aero LLC in furtherance of The Boeing Company’s electric aircraft joint venture with Kitty Hawk Corporation.
• Bloq, a blockchain technology solutions provider, in Illinois state court, defending against fraud allegations relating to the introduction and marketing of the token Metronome.
• The Litigation Oversight Committee to Genesis Global Holdco, LLC, against Genesis's parent Digital Currency Group and its founder and affiliated entities and individuals, on behalf of creditors who are owed crypto assets worth $2.2 billion, asserting claims for fraud, breach of fiduciary duty, unjust enrichment, preference, and fraudulent transfer, and involving coordination with federal and New York State regulators in parallel criminal and civil investigations and enforcement proceedings.
• Interpath, as Joint Liquidators of the BVI-based Kingate Global Fund and Kingate Euro Fund, in defending against breach of contract claims brought by Deutsche Bank Securities Inc. in the Southern District of New York, relating to DBSI’s alleged purchase from the Funds of more than $1.6 billion of claims against the Bernard Madoff estate. The parties reached a mediated settlement.
• The Weinstein Company as debtors’ counsel in connection with its bankruptcy and the sale of its assets.
• The Official Committee of Unsecured Creditors in the Chapter 11 case of Celsius Network LLC in the U.S. Bankruptcy Court for the Southern District of New York, acting as special litigation counsel to investigate and pursue causes of action against preferred equity holders on behalf of 1.7 million account users that used the Celsius platform before its bankruptcy filing.
• Hornblower Group, a global leader in experiences and transportation, representing the debtors as special litigation counsel in their Southern District of Texas Bankruptcy Court Chapter 11 cases with respect to a dispute with the debtors’ credit card processing vendor regarding the vendor’s credit card chargeback liabilities resulting from the cancellations of cruise trips by a subset of the Debtors, whose operations were winding down as part of the restructuring of Hornblower Group.

Claire earned her J.D. from Cornell Law School. Prior to joining Selendy Gay, Claire served as a law clerk for the Honorable Richard C. Wesley of the U.S. Court of Appeals for the Second Circuit and for the Honorable Brian M. Cogan for the U.S. District Court for the Eastern District of New York.