(312) 759-7221
William J. Katt

Mr. Katt practices in federal and state court. His practice focuses on commercial and family litigation. Mr. Katt advises lawyers and law firms on ethical issues, including representation in legal malpractice litigation. He frequently represents businesses and individuals in commercial litigation involving complex commercial fraud, patent infringement and other intellectual property violations, unfair competition, breach of contract, and employee separation issues. He also frequently represents high-net worth individuals in divorce and related proceedings.

Selected Engagements

Represented many large national law firms in legal malpractice and other actions involving intellectual property (patent and copyright), bankruptcy, commercial fraud, real estate, and other issues.

Represented numerous high-net worth individuals in divorce and related proceedings, with a focus on cases involving business interests or other complex financial assets and/or contested parenting issues.

Represented residential condominium association in litigation involving contract, property and fraud claims arising out of building conversion.

Represented founder and officer of technology startup in employment separation and related issues.

Defended arbitral body in various actions brought by disgruntled arbitration parties.

Represented taxi industry in litigation concerning unfair competition by “ridesharing” companies.

Represented major media outlet in litigation concerning access to public records.

Defended small business against qui tam litigation under the False Claims Act.

Represented public company and corporate officers in dispute with shareholder regarding convertible note.

Represented home equipment manufacturer in lawsuit involving breach of a patent license agreement.

Represented analytics company in dispute with competitor regarding patent infringement, unfair competition, and misappropriation of trade secrets.

Defended licensee of technology related to production methods of a chemical compound in breach-of-contract dispute with licensor.

Represented agricultural company in patent litigation against primary competitor regarding seed processing equipment.

Represented multiple pharmaceutical manufacturers in Hatch-Waxman litigation regarding pharmaceutical patent rights, including before the Federal Circuit.


B.S., Georgia Institute of Technology, Industrial Engineering, 2003

J.D., Northwestern University Law School, 2009
Graduated cum laude
Senior Articles Editor of Northwestern University Law Review
Lowden-Wigmore Prize for Legal Scholarship
Senior Research Honors


Admitted to the Illinois Bar, 2009

Law clerk to the Hon. Marvin E. Aspen, U. S. District Court for the Northern District of Illinois, 2009-2010

Law clerk to the Hon. Diane S. Sykes, U.S. Court of Appeals for the Seventh Circuit, 2010-2011

Associate with Latham & Watkins LLP, Chicago, Illinois, 2011-2014

Associate with this firm, 2014-2017; became a partner in 2018

Admitted to the bars of the U.S. District Court for the Northern District of Illinois, U.S. District Court for the Central District of Illinois, U.S. Court of Appeals for the Seventh Circuit, U.S. Court of Appeals for the Federal Circuit


Chicago Bar Association

American Bar Association

Selected Publications and Presentations

“Taylor v. Sturgell, Procedural Due Process, and the Day-in-Court Ideal: Resolving the Virtual Representation Dilemma,” Notre Dame Law Review, 2009. Written with Martin H. Redish.

“Roper and the Scientific Amicus,” Jurimetrics Journal, 2009.

“Res Judicata and Rule 19,” Northwestern University Law Review, 2009.