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 McDonnell Boehnen Hulbert & Berghoff LLP, Northwestern Pritzker School of Law, and Mayer Brown , LLP.

Top cities in Illinois

All practitioners in Illinois

David A Greenfield

Reg. 63760

Patent attorney

Mayer Brown , LLP

Chicago, IL · 60606

312-701-8188

Michael S Greenfield

Reg. 37142

Patent attorney

McDonnell Boehnen Hulbert & Berghoff LLP

Chicago, IL · 60606

312-913-0001

Steven H Greenfield

Reg. 58395

Patent agent

Greenfield Invention and Pattent Consulting, Inc.

Sycamore, IL · 60178

815-991-9420

Jason Phillip Greenhut

Reg. 71657

Patent attorney

Sidley Austin LLP

Chicago, IL · 60611

312-853-2144

Robert P Greenspoon

Reg. 40004

Patent attorney

Dunlap Bennett & Ludwig, PLLC

Chicago, IL · 60601

312-551-9500

Michael Jacob Gremillion

Reg. 81793

Patent agent

Lombard, IL · 60148

913-909-3761

John Joseph Gresens

Reg. 33112

Patent attorney

Akerman, LLP

Chicago, IL · 60606

312-634-5738

Percy E. Griffin

Reg. 83493

Patent agent

McDonnell Boehnen Hulbert & Berghoff LLP

Chicago, IL · 60606

312-913-3387

Christopher T Griffith

Reg. 33392

Patent attorney

Green, Griffith & Associates LLP

Chicago, IL · 60602

312-883-8000

Patrick Robert Grimaldi

Reg. 76852

Patent attorney

Lempia Summerfield Katz LLC

Chicago, IL · 60603

312-854-8375

Daniel A Griswold

Reg. 66008

Patent attorney

Deere & Company

Moline, IL · 61265

309-765-2148

Troy Alan Groetken

Reg. 46442

Patent attorney

Taft, Stettinius & Hollister LLP

Chicago, IL · 60601

312-527-4000

William J. Gros

Reg. 74276

Patent attorney

McNabola Law Group

Chicago, IL · 60601

630-740-7838

David R. Grosby

Reg. 75912

Patent attorney

Lee Sullivan Shea & Smith LLP

Chicago, IL · 60661

312-754-9423

Daniel P. Gross

Reg. 74535

Patent attorney

Kirkland & Ellis LLP

Chicago, IL · 60654

312-862-2613

Dennis A Gross

Reg. 24410

Patent attorney

The Hill Firm

Lake Forest, IL · 60062

847-509-0250

John Karl Gross

Reg. 57108

Patent attorney

Leydig, Voit & Mayer Ltd

Chicago, IL · 60601

312-616-5600

Jonathan E. Grossman

Reg. 63525

Patent attorney

Williams Montgomery & John

Chicago, IL · 60606

312-443-3858

Catherine T Grote

Reg. 83405

Patent attorney

Benesch Friedlander Coplan & Aronoff LLP

Chicago, IL · 60606

872-302-6460

Gregory D Grove

Reg. 43647

Patent attorney

Neal, Gerber & Eisenberg LLP

Chicago, IL · 60602

312-269-8084

Gary W. Grube

Reg. 76450

Patent agent

Caerus Institute

Barrington, IL · 60010

312-233-2854

Lewis S Gruber

Reg. 30060

Patent attorney

Chicago, IL · 60601

312-938-8740

Steven K Grumbine

Reg. 50449

Patent agent

Cabot Microelectronics CORP

Aurora, IL · 60504

630-375-5554

Matthew J Gryzlo

Reg. 43648

Patent attorney

McDermott Will & Emery LLP

Chicago, IL · 60606-5096

312-984-6874

Zheyuan Gu

Reg. 902874

Limited recognition

Northwestern Pritzker School of Law

Chicago, IL · 60611

646-886-8191

Kevin R Gualano

Reg. 64888

Patent attorney

Nixon Peabody LLP

Chicago, IL · 60602

312-425-8526

Li Guan

Reg. 902875

Limited recognition

Northwestern Pritzker School of Law

Chicago, IL · 60611

607-262-1943

Wendell R Guffey

Reg. 31762

Patent attorney

Swansea, IL · 62226

618-207-9596

Gregory B Gulliver

Reg. 44138

Patent attorney

Apogee Law Group P.C.

Grayslake, IL · 60030

847-984-3020

James C Gumina

Reg. 32898

Patent attorney

McDonnell Boehnen Hulbert & Berghoff

Chicago, IL · 60606

312-913-0001

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.