Patrick Sullivan focuses his practice on complex litigation. An accomplished litigator with extensive experience in life sciences and commercial defense, he regularly litigates seven-figure cases through trial in jurisdictions across the country, handling every aspect of litigation from pleading through appeal.

Pat’s life sciences litigation experience centers on the defense of medical professionals, drug and device manufacturers and entities – including hospitals, nursing homes and pharmacies – relative to allegations of professional negligence, misconduct and product liability.

He recognizes that the cornerstone of a strong life sciences defense is guiding the jury toward the appreciation of the unique and challenging circumstances faced by professionals and manufacturers in the field. He works closely with clients to help them better explain the intricacies of their specialized practice areas and products at deposition and trial.

Pat’s commercial litigation practice focuses on both the plaintiff and defense sides of litigation including contract disputes, corporate derivative actions, intellectual property litigation, cyber risk and liability litigation, and associated appellate work. Because commercial litigation is increasingly complex in the digitized world, he believes the best strategy for limiting risk is effective planning, review and oversight to maintain an informational edge and stay two steps ahead of the opponent.

Prior to joining Segal McCambridge, Pat was a trial litigator for both the plaintiffs and defense bars. This experience gives him institutionalized knowledge of procedure and a unique perspective on litigation strategy – a perspective he frequently shares through professional writing and presentations.

Pat graduated from UIC John Marshall Law School and received a B.S. in political science and economics from Bradley University.

Outside of work, he spends his time with his wife, two children and energetic Labrador.


  • Emerging Lawyers, 2018 – present

Professional & Civic Involvement

  • DRI
  • Claims and Litigation Management (CLM) Alliance
  • Professional Liability Defense Federation
  • Chicago Bar Association

Practice Highlights

Representative Matters

  • Secured victory for clients in the Illinois Supreme Court which issued a decision affirming riparian owners’ rights to protect property interests in creeks, rivers and streams
  • Obtained appellate victory supporting riparian rights and protecting against unauthorized use of private, non-navigable waterways by third parties.

News & Events



  • “Chapter 6: Products Liability,” contributing editor, LexisNexis Practice Guide: Illinois Personal Injury Litigation, LexisNexis, 2019 – present
  • “Chapter 5: Document Production and Organization,” Business and Commercial Litigation Handbook, Illinois Institute for Continuing Legal Education, 2019
  • “The Battle Over Rule 23: Authority v. Precedent,” co-author, DCBA Brief, DuPage County Bar Association, 2017

Speaking Engagements:

  • “The Opioid Crisis: Emerging Litigation and Insurance Coverage Issues,” The Knowledge Group, 2018