Takayuki Ono

TAKAYUKI (TAK) ONO represents global companies and their directors and officers in matters involving allegations of corporate misconduct, including board and special committee investigations, government and regulatory inquiries, and high-stakes litigation in U.S. courts.

Tak regularly leads matters arising from investigations and enforcement actions by the U.S. Department of Justice and the Securities and Exchange Commission, as well as litigation involving fraud, bribery, and antitrust claims. He is often engaged to manage cross-border crisis situations, navigate parallel proceedings, and coordinate defense strategy across jurisdictions.

He also advises companies on the strategic use of artificial intelligence in investigations, litigation, and compliance, with a focus on governance, defensibility, and the risk implications of emerging technologies.

Tak is bilingual in English and Japanese, placing him among the few U.S.-based litigators who combine that capability with deep experience leading cross-border enforcement and litigation matters.

Before joining Sidley, he practiced at another global law firm, representing clients in matters involving alleged anticompetitive conduct. Earlier in his career, he worked as a television news reporter for an ABC-affiliated station, where he conducted investigative reporting. He is also an FAA-certified commercial pilot.

Investigations, Enforcement & Crisis Management

• Representing a global financial services company in connection with a special committee investigation and defending the company in related securities and derivative litigation in federal court in Florida arising from an approximately US$18 billion write-down of an acquired business unit.
• Counseled a Japanese multinational company in crisis management matters and in internal and government investigations concerning allegations of corporate misconduct.
• Led cross-border internal investigations for a global healthcare company involving alleged Foreign Corrupt Practices Act issues.
• Conducted a sensitive internal investigation for a major energy company involving allegations concerning a senior executive.
• Advised on an investigation by the Securities and Exchange Commission involving a public company client of a global accounting firm.
• Counseled a senior executive of a Japanese manufacturing company in multi-agency U.S. investigations involving alleged corporate misconduct.
• Represented a leading healthcare company in a preliminary injunction trial involving antitrust claims brought by the U.S. Department of Justice concerning a proposed transaction.
• Advised clients in a Securities and Exchange Commission whistleblower matter involving allegations against a leading global investment firm.
• Handled civil investigative demands and regulatory inquiries in connection with antitrust matters involving major multinational companies.

High-Stakes Civil Disputes

• Representing a Japanese automaker in multidistrict litigation involving alleged defects in airbag control units and seatbelt systems.
• Representing a global financial institution in separate False Claims Act actions filed on behalf of the States of New York, Illinois, California, and New Jersey involving allegations related to the bank’s rate setting practices.
• Defended a global consumer health company in litigation involving allegations of securities fraud related to disclosures concerning over-the-counter medicine.
• Litigated matters involving a global telecommunications company concerning False Claims Act issues and disputes related to eligibility and reimbursement under federal funding programs.
• Represented a national retailer in high-stakes litigation involving technology-related commercial disputes with operational and financial implications.
• Defended a medical device sterilization company in litigation involving allegations of exposure to hazardous substances.
• Represented a Fortune 50 retail pharmacy and healthcare company in obtaining dismissal of a tortious interference claim in Delaware, later affirmed by the Delaware Supreme Court.

Some of the above matters were handled prior to joining Sidley.

• Tak serves on the board of governors of the Japanese American Bar Association (JABA) and is the founder of its Chicago Regional Committee. He is also active with the Japan America Society of Chicago.
• Tak served as chair of the associate board of the Chicago Committee on Minorities in Large Law Firms, after earlier terms as vice chair and secretary/treasurer.
• Tak has also served on the board of directors of the Asian American Bar Association of Greater Chicago and is a member of the National Asian Pacific American Bar Association (NAPABA).