Key contacts
Global Co-Chair of Simpson Thacher's Litigation Department: Lynn K. Neuner
Global Co-Chair of Simpson Thacher's Litigation Department: Jonathan K. Youngwood
Quick facts
Partners
315
Other qualified practitioners
1175
Practitioners (worldwide)
1490
Key practice areas
Bankruptcy
Insurance
Intellectual property
Dispute resolution
White collar crime
Securities
Competition/antitrust
Commercial
Firm overview
Sophisticated clients worldwide entrust us with their formidable disputes for a single reason–our remarkable track record. Clients seek our advice on high-stakes litigation and cross-border disputes, as well as government and internal investigations in the Americas, Europe and Asia.
Anti-Discrimination and DEI Advisory: Our practice is dedicated to providing comprehensive legal counsel and strategic guidance on matters relating to anti-discrimination laws and diversity, equity, and inclusion (DEI) initiatives. Our areas of focus include workplace investigations, litigation, legal compliance, culture and equity reviews, strategic counseling and training and education.
Antitrust and Trade Regulation: Clients turn to us for our record of success in handling high-stakes antitrust disputes, investigations, and achieving regulatory clearance for the largest and most complicated transactions. We advise clients on internal investigations, enforcement matters, and regulatory issues in connection with the OFAC, the Department of State, and the SEC.
Appellate: Our clients appreciate that Simpson Thacher is a formidable force in the appellate arena. They turn to us for our reputation for procuring against the odds, law-defining appellate rulings across a wide range of areas, including class actions, commercial, securities litigation, and pro bono.
Asset Management Litigation: Our team advises the world’s largest and most sophisticated investment managers and advisers on complex, high-stakes disputes and handles fund civil litigation, including litigation in federal and state courts, before arbitration tribunals, and in other forums across the globe. Our clients benefit from our extensive experience in the asset management industry where we take a holistic view in advising clients on their legal, regulatory, and compliance considerations. We also routinely advise on the potential for resolution of out-of-court disputes.
Asset Management Regulatory and Enforcement: Our team includes attorneys with decades of experience in the funds industry, former senior government officials from the SEC, and former U.S. federal prosecutors, who draw upon their deep experience and institutional knowledge to provide sophisticated advice to clients on a broad spectrum of critical regulatory and compliance issues.
Bankruptcy Litigation: Our comprehensive practice covers all aspects of bankruptcy-related litigation–from disputes over plan confirmation to tender liability and equitable subordination claims to issues arising out of insurance disputes and mass tort-related bankruptcies.
ERISA Litigation: Clients benefit from our coordinated advice in closely aligned areas, including securities, bankruptcy, and government investigations, and our ability to present arguments and evidence in the manner best suited to advance business interests and resolve conflicts with minimal disruption to their operations.
False Advertising Litigation: Companies in a broad range of fields, including pharmaceuticals, financial services, consumer products and food and beverage, turn to us for our significant experience in false advertising litigation, including disputes between competitors and consumer class actions, as well as for ongoing regulatory guidance.
Government and Internal Investigations: Large and small companies and their boards, audit and special committees, officers and directors, and other individuals regularly turn to us for advice on a wide range of criminal, regulatory, congressional and other sensitive government inquiries and internal investigations.
Insurance and Reinsurance: Clients benefit from our experience as the leading firm representing the interests of both ceding companies and reinsurers in litigations and arbitrations throughout the United States, the United Kingdom and Bermuda. Major insurance groups, including Travelers, AIG, Berkshire Hathaway, Lloyd’s of London and CNA have trusted us on their most significant matters.
Intellectual Property Litigation: Understanding and protecting IP is crucial to the long-term success of many businesses. Clients seek our advice in high-stakes, “make it or break it” disputes and rely on our broad array of substantive experience in both litigation and transactional matters to help them protect their interests. We unite sophisticated litigation skills with a deep understanding of all types of intellectual property, including patents, copyrights, trade secrets and proprietary data, software, and trademarks.
International Disputes and Arbitration: We handle high-stakes international disputes and commercial crises, where the outcome is uncertain and our clients need the highest quality of service. Our collaborative team operates worldwide from the Firm’s London office. The scope of our practice from the London office reaches across all of North and South America, Europe, the Middle East and Asia-Pacific.
International Regulatory and Compliance: With increased activism and cross-border cooperation between enforcement and regulatory agencies, we represent the interests of a wide array of clients operating in multiple jurisdictions and have advised on issues in China, India, Eastern Europe, the Middle East, Latin America and Africa.
Mergers and Acquisitions Litigation: Clients seek our market-leading advice in all aspects of M&A litigation—where we excel at defending challenges to the largest and most complex mergers and acquisitions. They appreciate our extensive experience defeating efforts to enjoin transactions prior to closing; resolving claims through reasonable settlements pre-closing; and litigating claims for damages post-closing.
Privacy and Cybersecurity: Our multidisciplinary Privacy and Cybersecurity team advises global companies facing heightened regulatory, contractual and consumer obligations surrounding the management of data, including personal data and use of AI.
Product Liability and Mass Tort: Since the 1970s, clients have relied on our advice as a leader in the development of product liability and mass tort law in the United States. We have taken countless product liability and mass tort cases to jury trial in state and federal courts over the years, amassing invaluable courtroom experience.
Securities: For decades, clients have relied on our securities litigators in the most complex, high-profile, high-stakes securities matters of the day. The country’s most respected Fortune 500 corporations and financial institutions turn to us to help defend against headline-making allegations.
Whistleblower and False Claims Act: Companies and their boards have relied on us to respond to allegations by whistleblowers and to help them devise and implement corporate whistleblower policies. Clients seek our counsel on whistleblower matters in a broad range of sectors—including defense, healthcare, technology and financial services.
Updated Oct 2025
Connect with us
Key practice areas
- Appellate
- Arbitration
- Bankruptcy
- Class action
- Commercial
- Commercial and transactions
- Commercial disputes
- Competition/antitrust
- Dispute resolution
- EU Competition
- Government and regulatory
- Insolvency
- Insurance
- Intellectual property
- International arbitration
- Securities
- Trade and customs
- White collar crime
- Advertising Litigation
- Anti-Discrimination Litigation and Advisory
- Asset Management Litigation
- ERISA Litigation
- International Disputes and Arbitration
- Mergers and Acquisitions Litigation
- Privacy and Cybersecurity
Key practice contacts
- Lynn K. Neuner
Commercial disputes
E: lneuner@stblaw.com
- Jonathan K. Youngwood
Securities
E: jyoungwood@stblaw.com
Sector expertise
Other offices
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Address:
Tel:+1 212 455 2000
Fax:+1 212 455 2502
Email:Contact Us
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