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 Hallihan IP Partners, LLC, R. Elliott Halsey, P.C., and Law Office of Zachary Hamilton.

Top cities in Illinois

All practitioners in Illinois

Christian H. Hallerud

Reg. 82498

Patent attorney

Wheaton, IL · 60187

630-200-6936

William J Hallihan

Reg. 39210

Patent attorney

Hallihan IP Partners, LLC

Chicago, IL · 60661

312-784-3000

Clinton H Hallman· Jr

Reg. 38480

Patent attorney

Lake Forest, IL · 60045

804-350-9791

Richard Elliott Halsey

Reg. 46752

Patent attorney

R. Elliott Halsey, P.C.

Wheaton, IL · 60187-4731

312-505-1474

Brian William Hameder

Reg. 45613

Patent attorney

Park Ridge, IL · 60068

312--21-3-4305

Zachary Hamilton

Reg. 39212

Patent attorney

Law Office of Zachary Hamilton

Crete, IL · 60417

708-514-4761

Lesley M Hamming

Reg. 66986

Patent attorney

Latham & Watkins LLP

Chicago, IL · 60611

312-876-7700

Eric J Hamp

Reg. 68971

Patent attorney

Banner & Witcoff, Ltd.

Chicago, IL · 60606

312-463-5472

Nathaniel A. Hamstra

Reg. 65680

Patent attorney

Quinn Emanuel Urquhart & Sullivan, LLP

Chicago, IL · 60606

312-705-7400

Mark G Hanley

Reg. 44736

Patent attorney

Hanley, Flight & Zimmerman, LLC

Chicago, IL · 60606

312-580-1020

Megan K. Hanley

Reg. 79916

Patent agent

McDonnell, Boehnen, Hulbert & Berghoff LLP

Chicago, IL · 60606

312-913-2350

Steven Michael Hanley

Reg. 46756

Patent attorney

CATERPILLAR INC.

Peoria, IL · 61629

309-494-4045

Alfred E Hanna

Reg. 57605

Patent attorney

Clinical Investigation Specialists, Inc.

Gurnee, IL · 60031

630-258-7898

Mary Theresa Hannon

Reg. 77149

Patent agent

Sidley Austin LLP

Chicago, IL · 60603

312-423-3452

Daniel I Hanrahan

Reg. 63327

Patent attorney

The Marmon Group LLC

Chicago, IL · 60602

312-372-9500

James P Hanrath

Reg. 31965

Patent attorney

Much Shelist Freed Denenberg Ament & Rubenstein, P.C.

Chicago, IL · 60606-1615

312-521-2760

Leland G Hansen

Reg. 50731

Patent attorney

McAndrews Held and Malloy LTD

Chicago, IL · 60661

312-775-8000

Elese E. Hanson

Reg. 62118

Patent attorney

Duane Morris, LLP

Chicago, IL · 60603-3433

312-499-0114

Ernest J Hanson

Reg. 62955

Patent agent

Brown & James, P.C.

Belleville, IL · 62220

618-235-5590

Karl R Hanson

Reg. 72277

Patent attorney

Nokia

Naperville, IL · 60563

000-000-0000

Rekha Hanu

Reg. 54916

Patent agent

Duane Morris LLP

Chicago, IL · 60603

312-499-6702

Anthony Hao

Reg. 79496

Patent attorney

Chicago, IL · 60661

816-457-0158

Aeraj U Haque

Reg. 73668

Patent attorney

Cooley LLP

Chicago, IL · 60606

312-881-6714

Mark C Harbeck

Reg. 71696

Patent agent

Lisle, IL · 60532

630-479-0592

John W Harbst

Reg. 28018

Patent attorney

Law Office Of John W Harbst

Bartlett, IL · 60103

630-289-4839

Christopher A Harkins

Reg. 48775

Patent attorney

State Farm Mutual Automobile Ins. Co.

Bloomington, IL · 61710-0001

800-782-8332

Michael Bernard Harlin

Reg. 43658

Patent attorney

Neal, Gerber & Eisenberg LLP

Chicago, IL · 60602

312-269-8000

Ren-How H. Harn

Reg. 73620

Patent attorney

Willkie Farr & Gallagher

Chicago, IL · 60654

312-728-9028

Margaret C Harney

Reg. 80885

Patent agent

Morgan, Lewis & Bockius LLP

Chicago, IL · 60606-1511

312-324-1727

Timothy Louis Harney

Reg. 38174

Patent attorney

U.S. Department of Energy

Lemont, IL · 60439

331-444-0618

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.