Ken Sullivan

Managing Partner

Ken Sullivan is a founding member of Sullivan Royko. Before founding the firm, Ken was a partner at The Quinlan Law Firm, LLC, Tressler, LLP, Hedlund Hanley Koenigsknecht & Trafelet, and Gardner Carton & Douglas, LLP, which later merged with Drinker Biddle. Additionally, Ken previously managed his own firm, Sullivan & Associates, LLC.

Prior to Ken’s experience in the private sector, Ken was an Illinois Assistant Attorney General. Ken has represented clients across the United States in federal courts, arbitration, mediation, and in multiple public service commissions. Ken has also been engaged as separate trial counsel for the specific task of trying claims to multiple tribunals.

Ken is a trial attorney with more than 30 years of litigation experience representing both the public and private sectors. Ken has brought over 15 civil jury trials to verdict, first-chaired multiple bench trials in state and federal courts, and regularly represents clients in injunctive and other equitable relief hearings, administrative hearings, arbitrations, and mediations.

In the private sector, Ken has successfully represented business entities of all sizes ranging from individual or family-owned businesses to Fortune 500 companies. His experience ranges from matters involving consumer class action litigation, securities fraud litigation, prominent antitrust litigation, complex contract actions, business torts, accounting and legal malpractice actions, prominent First Amendment litigation, employment litigation, lender liability litigation, bankruptcy adversary proceedings, professional licensing matters, real estate litigation, derivative actions, general commercial litigation, and civil rights litigation.

Ken has extensive experience in a wide variety of civil litigation matters, including class actions, employment discrimination litigation, and constitutional law matters. As a Special Assistant Attorney General, Ken has also represented the Governor, Secretary of State and other cabinet level, and state officials.

Ken has also served as outside general counsel for a variety of corporations and small businesses. These include organizations in multiple industries, including but not limited to the real estate, refinery, and chemical industries. Ken’s duties as outside general counsel have been to field all problems a corporation or organization face on a daily basis.

In addition, Ken has significant experience advising clients on the litigation risks of cyber liability and compliance with state and federal privacy laws. Relying on his experience with commercial litigation, class action lawsuits, and creditors’ rights, Ken advises clients on the consequences and potential damages after a data breach and provides clients with a litigation strategy before a lawsuit being filed as well as after litigation has been initiated seeking damages related to unauthorized disclosure of personal information.

Ken is a true Chicagoan; he is a graduate of The John Marshall Law School and attended Northern Illinois University for his Undergraduate Degree. Since majoring in political science, Ken has always been motivated to be the best advocate, litigator, and trial lawyer he could be in and out of the courtroom. Ken’s passion for his client’s interests has consistently positioned him as an advocate, asset, and friend during multiple engagements.

Notable Representation

  • Defended an online optics retailer from a 13-count complaint, including Lanham Act violations, cybersquatting, trademark dilution, Illinois Consumer Fraud, and Deceptive Business Practice Act violations and tortious interference with business expectancy.
  • Jointly defended six individuals in a complaint alleging breach of contract related to an alleged participation in a diversion ring concerning a trademarked product obtained directly from the plaintiff and allegedly sold via the Internet in violation of individual sales representative contracts.
  • Defended an investor in an SBIC Act limited liability company against claims for $1.4 million.
  • Defended a petroleum byproducts refinery in claims alleging breach of contract concerning the distribution of recycled petroleum byproducts.
  • Represented a U.K. based furniture designer in a fraud and patent infringement case brought against an Illinois furniture manufacturer and distributor.
  • Defended a mid-sized chemical distributor in a complaint alleging Illinois Trade Secret Act violations and theft of intellectual property.
  • Represented a real estate developer on a $200 million-dollar corporate transaction in the state of Arizona based on defendant’s implied duties of good faith and fair dealing
  • Provided outside general counsel work for an Arizona corporation with revenues exceeding $30 Million per year.
  • Prosecuted claims against a residential real estate development corporation for Illinois Consumer Fraud Act, breach of contract, and recessionary claims based upon misrepresentations of condominium square footage.
  • Prosecuted legal malpractice, common law fraud, and breach of fiduciary duty claims on behalf of a former pension fund administrator against his former attorneys.
  • Defended a residential construction firm against claims alleging breach of contract and Illinois Consumer Fraud Act claims over retention of non-refundable earnest money.
  • Represented a Texas-based petroleum production company from claims brought by federal court receivers for client’s alleged participation in an alleged Ponzi scheme.


  • J.D., The John Marshall Law School
  • B.A., Northern Illinois University


  • State of Illinois Bar
  • United States Supreme Court
  • Supreme Court of Illinois
  • U.S. Court of Appeals, 7th Circuit
  • U.S. Court of Appeal, 9th Circuit
  • Trial Bar of the Northern District of Illinois
  • U.S. District Court, Northern District of Illinois
  • U.S. District Court, Central District of Illinois
  • U.S. District Court, Southern District of Illinois
  • United States Tax Court