Illinois

Patent attorneys in Illinois

Illinois hosts 2,889 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, Molex, LLC, and McCracken & Frank LLP.

Top cities in Illinois

All practitioners in Illinois

Gavin J O'Keefe

Reg. 59916

Patent attorney

McDonnell Boehnen Hulbert & Berghoff LLP

Chicago, IL · 60606

312-913-0001

James A O'Malley

Reg. 45952

Patent attorney

Molex, LLC

Lisle, IL · 60532

630-718-5534

Edward M O'Toole

Reg. 22477

Patent attorney

McCracken & Frank LLP

Chicago, IL · 60606

312-422-5613

Jimmie R Oaks

Reg. 24987

Patent attorney

Coal Valley, IL · 61240

309-234-5552

William P Oberhardt

Reg. 31861

Patent agent

Olson & Cepuritis

Chicago, IL · 60606

312-580-1180

Adnan Mohamad Obissi

Reg. 75081

Patent attorney

Chicago, IL · 60622

312-848-2773

Paul M Odell

Reg. 28332

Patent attorney

Wood Phillips Katz Clark & Mortimer

Chicago, IL · 60661

312-876-2116

James Matthew Oehler

Reg. 68591

Patent attorney

McDermott Will & Emery

Chicago, IL · 60606

312-899-7277

Douglas A Oguss

Reg. 48469

Patent attorney

Crowell & Moring LLP

Chicago, IL · 60611

312-321-4785

Hyun Oh

Reg. 74479

Patent agent

Chicago, IL · 60605

703-505-1291

Glenn W Ohlson

Reg. 28455

Patent attorney

Barnes & Thornburg LLP

Chicago, IL · 60606

312-357-1313

Ifeyinwa O. Okafor

Reg. 82267

Patent attorney

Gurnee, IL · 60031

614-214-8737

Joseph P. Oldaker

Reg. 62041

Patent attorney

Oldaker Law, P.C.

Winnetka, IL · 60093

312-957-4230

Wallace L Oliver· Jr

Reg. 27368

Patent attorney

Applied Thin films Inc.

Skokie, IL · 60077

847-436-1094

Arne M Olson

Reg. 30203

Patent attorney

Olson & Cepuritis, Ltd.

Chicago, IL · 60606-3103

312-580-1180

Ragnar Richard Olson

Reg. 58684

Patent attorney

Global IP Law Group, LLC

Chicago, IL · 60603

312-241-1500

Thomas Evan Omholt

Reg. 37052

Patent agent

Cabot Microelectronics Corporation

Aurora, IL · 60504

630-375-2033

Jordan T. One

Reg. 74085

Patent agent

Greenberg Traurig, LLP

Chicago, IL · 60601-1732

312-456-6587

Oliver T Ong

Reg. 58456

Patent attorney

Marshall, Gerstein & Borun, LLP

Chicago, IL · 60606

312-474-6300

Micah R Onixt

Reg. 47834

Patent attorney

Piper Marbury Rudnick and Wolfe

Chicago, IL · 60601

312-368-2141

Anna A. Onley

Reg. 73876

Patent attorney

Chicago, IL · 60625

773-960-2476

Neil Randall Ormos

Reg. 35309

Patent attorney

Arlington Heights, IL · 60005

224-366-7104

Brian Robert Orr

Reg. 56694

Patent attorney

Mokena, IL · 60448

815-485-7408

Andrea K Orth

Reg. 68000

Patent attorney

GrowIP Law Group LLC

Barrington, IL · 60010

312-823-6864

David D. Osinski

Reg. 82060

Patent agent

Hanley, Flight, and Zimmerman, LLC

Chicago, IL · 60606

312-580-1020

David N Oskin

Reg. 58863

Patent attorney

Keeper Security, Inc.

Chicago, IL · 60607

708-515-4062

John J Oskorep

Reg. 41234

Patent attorney

Chicago, IL · 60611

312-222-1860

Sherri L Oslick

Reg. 52087

Patent attorney

McDonnell Boehnen Hulbert & Berghoff LLP

Chicago, IL · 60606

312-913-0001

Michael Robert Osterhoff

Reg. 46973

Patent attorney

K&L Gates LLP

Chicago, IL · 60602-4207

312-807-4205

Jeffrey A Ostrom

Reg. 67146

Patent attorney

Bourbonnais, IL · 60914

815-936-9373

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?

2,889 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.