Illinois

Patent attorneys in Illinois

Illinois hosts 2,917 active patent practitioners registered with the USPTO Office of Enrollment and Discipline. Patent attorneys and patent agents can both prepare and file patent applications, but only patent attorneys can also offer legal advice on prosecution strategy, freedom-to-operate analyses, and infringement opinions in Illinois. Practitioners are concentrated across 20 cities, with the largest clusters in the metros listed below. Notable firms with multiple registered practitioners in the state include Cook Alex Ltd., Marshall, Gerstein & Borun LLP, and Hanley, Flight & Zimmerman, LLC.

Top cities in Illinois

All practitioners in Illinois

Peter Hyunmin Yu

Reg. 76398

Patent agent

HERE North America, LLC

Chicago, IL · 60606

312-208-4155

Qi Yu

Reg. L1384

Limited recognition

Banner & Witcoff, Ltd.

Chicago, IL · 60606

312-616-5712

Shui Wan Yu

Reg. 81939

Patent agent

Cook Alex Ltd.

Chicago, IL · 60606

312-368-500

Arthur Tan Chi Yuan

Reg. 62449

Patent attorney

Loeb & Loeb LLP

Chicago, IL · 60654

312-464-3152

Shelby C. Yuan

Reg. 84493

Patent attorney

Latham & Watkins LLP

Chicago, IL · 60611

312-777-7280

Maya Yusim

Reg. 73563

Patent agent

Faegre Drinker Biddle & Reath

Chicago, IL · 60606

312-569-1506

David Paul Yusko

Reg. 30817

Patent attorney

INEOS USA LLC

Lisle, IL · 60532

630-857-7151

John M. Zaborske

Reg. 73211

Patent agent

Oak Park, IL · 60302

773-480-2494

Philip John Zadeik

Reg. 31444

Patent attorney

Weber-Stephen Products LLC

Palatine, IL · 60067

224-836-2606

Jenna E. Zaengle

Reg. 84224

Patent agent

Libertyville, IL · 60048

847-421-6499

Christopher B. Zahn

Reg. 83235

Patent attorney

Marshall, Gerstein & Borun LLP

Chicago, IL · 60606

312-423-3459

Florina B Zaitseva

Reg. 53824

Patent attorney

Skokie, IL · 60077

847-965-8307

Constance L Zanardo

Reg. 55409

Patent attorney

Illinois Appellate Court

Long Grove, IL · 60047

847-821-1763

Dominic P Zanfardino

Reg. 36068

Patent attorney

Brinks Gilson & Lione

Chicago, IL · 60611-5599

312-321-4287

Robert J Zeitler

Reg. 37973

Patent agent

Molex INC

Lisle, IL · 60532

630-969-4550

James Paul Zeller

Reg. 28491

Patent attorney

Marshall, Gerstein & Borun LLP

Chicago, IL · 60606

312-474-6300

Steven McMahon Zeller

Reg. 48060

Patent attorney

Dykema Gossett PLLC

Chicago, IL · 60606

312-627-2272

Blaine J Zern

Reg. 75047

Patent agent

Michael Best & Friedrich LLP

Chicago, IL · 60606

312-596-5833

Allen G Zeyher

Reg. 50550

Patent agent

Chicago, IL · 60657

773-871-8012

Weian Zhan

Reg. 66752

Patent attorney

Chicago, IL · 60605

847-298-2996

Daniel G Zhang

Reg. 78856

Patent agent

Irwin IP LLC

Chicago, IL · 60607

312-667-6199

Rao Zhang

Reg. 59097

Patent agent

Vernon Hills, IL · 60061

312-451-2468

Shu Zhang

Reg. 75882

Patent attorney

Riley Safer Holmes & Cancila LLP

Chicago, IL · 60603

312-471-8740

Shuang Zhang

Reg. 75778

Patent agent

Faegre Baker Daniels LLP

Chicago, IL · 60606

312-212-6557

Xu Zhang

Reg. 68601

Patent attorney

AbbVie Inc.

North Chicago, IL · 60064

847-935-1133

Lloyd L Zickert

Reg. 17807

Patent attorney

Cook Alex Ltd.

Chicago, IL · 60606

312-236-8500

Amy C. Ziegler

Reg. 56099

Patent attorney

Greer, Burns & Crain, Ltd

Chicago, IL · 60606

312-360-0080

Greta T. Zimmerman

Reg. 83363

Patent agent

Banner Witcoff

Chicago, IL · 60606

312-463-5000

Mark C Zimmerman

Reg. 44006

Patent attorney

Hanley, Flight & Zimmerman, LLC

Chicago, IL · 60606

131-258-01094

Michael W. Zimmerman

Reg. 57993

Patent attorney

Hanley, Flight & Zimmerman, LLC

Chicago, IL · 60606

312-580-1020

Common questions

Do I need a patent attorney based in Illinois?

No. Every USPTO-registered patent practitioner is licensed to file applications on behalf of inventors in any state, regardless of where the practitioner's office is. Choosing a Illinois-based practitioner can simplify in-person inventor signings, local meetings, and same-time-zone calls, but it is not a legal requirement.

How many patent attorneys are licensed in Illinois?

2,917 active USPTO-registered patent practitioners list a Illinois office address on the OEDCI roster. This includes both patent attorneys (who can also offer legal advice) and patent agents (who can prepare and file patents but not offer broader legal advice).

What is the difference between a patent attorney and a patent agent?

Both pass the USPTO Patent Bar and can prepare, file, and prosecute patent applications. Only patent attorneys also hold a state bar license, meaning they can additionally offer legal advice on infringement, licensing, and litigation strategy. Patent agents tend to charge less per hour and are common at large in-house IP departments.