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 Marshall, Gerstein & Borun LLP, Perry Svcs, and Mahoney & Mahoney, LLC.

Top cities in Illinois

All practitioners in Illinois

Michael J Perry

Reg. 53451

Patent attorney

Perry Svcs

Zion, IL · 60099

847-872-8920

Sara Ellen Stephenson Peska

Reg. 62350

Patent attorney

Mahoney & Mahoney, LLC

Freeport, IL · 61032

815-656-4600

James T. Peterka

Reg. 59186

Patent attorney

Locke Lord LLP

Chicago, IL · 60606-4410

312-443-0270

Aaron Michael Peters

Reg. 48801

Patent attorney

Marshall, Gerstein & Borun LLP

Chicago, IL · 60606

312-474-6300

Elizabeth A Peters

Reg. 68470

Patent attorney

Riverside, IL · 60546

708-853-9865

Grant Henry Peters

Reg. 35977

Patent attorney

Barnes & Thornburg, LLP

Chicago, IL · 60606

312-214-8332

Louis Michael Peters

Reg. 82268

Patent attorney

Peters Law, LLC

Aurora, IL · 60504

401-384-0753

Nicholas T Peters

Reg. 53456

Patent agent

Fitch Even Tabin and Flannery

Chicago, IL · 60603

312-577-7000

Ann C Petersen

Reg. 55536

Patent attorney

Cardinal Law Group

Evanston, IL · 60201

408-223-2718

Maxwell James Petersen

Reg. 32772

Patent attorney

FisherBroyles LLP

Arlington Heights, IL · 60005

847-873-1116

Steven P Petersen

Reg. 32927

Patent attorney

Leydig Voit and Mayer, Ltd.

Chicago, IL · 60601

312-616-5600

Lucas A. Peterson

Reg. 81460

Patent attorney

Blank Rome LLP

Chicago, IL · 60606

312-776-2603

Shawn Leonard Peterson

Reg. 44286

Patent attorney

McAndrews Held and Malloy, Ltd.

Chicago, IL · 60661

312-775-8000

Timothy F Peterson

Reg. 58457

Patent attorney

Buchanan Ingersoll & Rooney PC

Chicago, IL · 60606

312-261-8777

John A Petravich

Reg. 53460

Patent attorney

Integrated DNA Technologies, Inc.

Skokie, IL · 60077

847-745-1700

George R Petrilli

Reg. 75024

Patent attorney

Springfield, IL · 62704

217-725-5614

Philip Todd Petti

Reg. 31651

Patent attorney

USG Corporation

Chicago, IL · 60565

312-436-4590

David Z Petty

Reg. 52119

Patent attorney

McAndrews Held and Malloy LTD

Chicago, IL · 60661

312-775-8000

Gwen G Phanijphand

Reg. 74146

Patent agent

Chicago, IL · 60622

703-608-9058

Ryan N. Phelan

Reg. 60674

Patent attorney

Marshall, Gerstein & Borun LLP

Chicago, IL · 60606-6357

312-474-6300

Mark Edwin Phelps

Reg. 28461

Patent attorney

Leydig, Voit & Mayer LTD

Chicago, IL · 60654

312-616-5600

W Garland Phillips

Reg. 66521

Patent agent

Banner & Witcoff, LTD

Chicago, IL · 60606

312-463-5000

Justin Michael Philpott

Reg. 59945

Patent attorney

Banner Witcoff

Chicago, IL · 60606

312-463-5000

Ryan J. Pianetto

Reg. 68885

Patent attorney

McAndrews, Held & Malloy, Ltd.

Chicago, IL · 60661

312-775-8000

David J. Piasecki

Reg. 53467

Patent agent

UOP

Des Plaines, IL · 60017

847-391-3146

Alec Joseph Piatigorsky

Reg. 903015

Limited recognition

University of Illinois Chicago School of Law

Chicago, IL · 60604

773-575-9503

Cameron B. Pick

Reg. 71172

Patent agent

Marshall, Gerstein & Borun LLP

Chicago, IL · 60606

312-474-6300

Mackenzie S. Pike

Reg. 81636

Patent attorney

Chicago, IL · 60654

312-862-2000

Kyle M. Pikula

Reg. 82166

Patent agent

Palos Park, IL · 60464

708-642-3432

Sophia P. Pilipchuk

Reg. 79246

Patent agent

Hanley, Flight & Zimmerman, LLC

Chicago, IL · 60606

312-676-1737

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.