John Sullivan

Cozen O'Connor PC

John J. Sullivan practices in the firm’s Commercial Litigation Department and has nearly two decades of experience handling a wide variety of complex litigation. He defends companies in securities, corporate governance, antitrust, product liability, class action, mass tort, and other business litigation.

John regularly represents global companies in the life sciences, chemical, banking, venture capital, fund management, and real estate industries.

In the area of financial litigation, John defends clients in state and federal courts in disputes involving contested takeovers, securities class actions, investigations by the SEC Division of Enforcement, contested mutual fund rights offerings, RICO claims, fraud claims in insurance company insolvency proceedings, and commercial real estate contract disputes. He often advises mutual funds and banks on litigation and regulatory issues.

John has also served on trial defense teams in some of the largest and most challenging products liability and mass tort litigation in the last decade. He has defended companies in coordinated proceedings involving claims of failure to warn, consumer fraud, manufacturer and design defect, and warranty and breach of contract.

A well-rounded commercial litigator, John has deep experience managing attorneys conducting case-specific discovery, defending witnesses, handling evidentiary and coordination hearings, negotiating with opponents, and deposing and defending expert witnesses. He has litigated constitutional and preemption issues, dealt with regulatory agencies and their regulations, and represented clients in appellate proceedings before state and federal appellate courts, including the United States Supreme Court.

Before joining Cozen O’Connor John was a partner Dechert LLP, and he started his career at Sullivan & Cromwell. For John’s considerable success, he has been recognized by Benchmark Litigation as a “future star” in their 2009 and 2010 editions and an “innovative lawyer” by the Financial Times in 2011.

John is a frequent author and speaker at legal conferences, and he is often asked to comment on current litigation in the legal media. He is an author of the Class Action Defense Review, as well as the Drug & Device Law Blog, one of the most well-respected product liability litigation blogs.

John earned his law degree from Rutgers School of Law-Newark, where he was awarded the Order of the Coif and was a two-time Saul Tischler Scholar. He received his bachelor’s degree from Rutgers University, New Brunswick.


  • Represented an investment bank against state and federal securities law claims, RICO claims, and common law claims asserted in connection with the offering of junk bonds to fund the construction of a steel mill in South East Asia. The cases were filed in multiple state and federal courts across the country, including in California.
  • Defended UK venture capital firms in California state court against a securities class action brought by investors seeking tens of millions of dollars in damages. The investors alleged California securities and common law claims. The case was dismissed with prejudice on demurrer.
  • Defended a fund management company in federal court against class action claims brought under the Investment Company Act, the Securities Exchange Act and Maryland common and statutory law. After filing a motion to dismiss and convincing the court to stay the action, the matter settled.
  • Advised fund management companies on (i) securities and corporate governance issues of potential acquisition targets and (ii) potential avenues of redress under the securities laws with regard to ongoing scandals.
  • Defended medical device company in the Commercial Division of the New York Supreme Court in mass-tort litigation that sprung from the withdrawal of one of its products from the market.
  • Defended large venture capital fund in both Delaware Chancery and Colorado state court in connection with a dispute over convertible debentures. Successfully stayed the Colorado action, which was in the plaintiff’s home state, and the matter settled once it was proceeding solely in Delaware court.
  • Defended venture capital fund and two related entities in connection with challenge to proposed leveraged buyout of a public company filed on an expedited basis in New Jersey chancery court.
  • Defended insurance holding company in federal court against securities class action involving claims brought under the Securities Act of 1933, the Securities Exchange Act of 1934, and their relevant control person provisions.
  • Defended a medical imaging subsidiary of healthcare services company against a contract claim. Won a complete dismissal of the action by filing a motion to dismiss at the start of the litigation.


  • Rutgers University School of Law—Newark, J.D., 1996
  • Rutgers University, New Brunswick, B.A., 1992

BAR ADMISSIONS : New York; New Jersey


  • U.S. Supreme Court
  • U.S. Court of Appeals for the Second Circuit
  • U.S. District Court — New Jersey
  • U.S. District Court — Southern District of New York
  • U.S. District Court — Eastern District of New York


Rate : $$$

What types of cases Attorney John Sullivan & Cozen O'Connor PC can handle?
Cozen O'Connor PC can handle cases related to laws concerning Real Estate, Litigation, Construction, Class Action, Business, Health Care, Venture capital, Antitrust & Trade, Product Liability. We manually verify each attorney’s practice areas before approving their profiles and reviews on our website.
Where is Cozen O'Connor PC located?
Cozen O'Connor PC is located at 457 Haddonfield Rd, Cherry Hill, NJ 08002, USA. You can reach out to Cozen O'Connor PC using their phone line (856) 910-5067. You can also check their website or email them at [email protected].
How much would it cost to hire Cozen O'Connor PC?
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Cozen O'Connor PC
457 Haddonfield Rd, Cherry Hill, NJ 08002, USA
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