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 Caterpillar Inc., Fitch Even Tobin & Flannery, LLP, and Rakoczy Molino Mazzochi Siwik LLP.

Top cities in Illinois

All practitioners in Illinois

Jennifer L. Soerensen

Reg. 78895

Patent agent

Fitch Even Tobin & Flannery, LLP

Chicago, IL · 60603

312-577-7000

Daniel Sokoloff

Reg. 78516

Patent attorney

Rakoczy Molino Mazzochi Siwik LLP

Chicago, IL · 60654

312-222-7207

Derek J. Somogy

Reg. 66833

Patent attorney

Caterpillar Inc.

Peoria, IL · 61629

309-494-4483

Hyojeong Son

Reg. 82325

Patent attorney

LEMPIA SUMMERFIELD KATZ LLC

Chicago, IL · 60604

312-291-0860

Jingfeng Song

Reg. 67105

Patent attorney

SciNova IP and Regulatory Consulting LLC

Barrington, IL · 60010

224-619-9822

Viren S Soni

Reg. 65824

Patent attorney

CME Group

Chicago, IL · 60606

312-338-2823

Russell E Sorber

Reg. 55637

Patent agent

Sorber Associates

Oak Park, IL · 60304

224-355-7432

Christopher T Sorce

Reg. 66872

Patent attorney

Sorce Law, LLC

Glen Ellyn, IL · 60138

630-344-9674

Leonard S Sorgi

Reg. 33211

Patent attorney

Chicago, IL · 60640

917-848-0525

Elias P Soupos

Reg. 57375

Patent attorney

Fitch, Even, Tabin & Flannery LLP

Chicago, IL · 60603

312-629-7908

William C Spangler

Reg. 78991

Patent agent

Peonia, IL · 61614

309-992-8083

Sean C. Sparrow

Reg. 76482

Patent attorney

McAndrews, Held & Malloy, LTD.

Chicago, IL · 60661

847-668-7873

Nicholas J R Spear

Reg. 69328

Patent attorney

Grossman Law Office

Chicago, IL · 60606

612-621-9000

William C Spence

Reg. 48186

Patent attorney

SpencePC

Chicago, IL · 60654

312-404-8882

Milena J Spencer

Reg. 70274

Patent attorney

Chicago, IL · 60614

847-287-5428

Jonathan M Spenner

Reg. 57268

Patent attorney

Leydig, Voit & Mayer, Ltd.

Chicago, IL · 60601-6731

312-616-5600

Kenneth P Spina

Reg. 43927

Patent attorney

Leydig Voit and Mayer, Ltd.

Chicago, IL · 60601-6780

312-616-5600

Andrew M. Spitzer

Reg. 79411

Patent agent

Chicago, IL · 60610

Ronald H Spuhler

Reg. 52245

Patent attorney

McAndrews Held and Malloy LTD

Chicago, IL · 60661

312-775-8000

Sonali S Srivastava

Reg. 52248

Patent attorney

AbbVie, Inc.

Abbott Park, IL · 60064

847-937-4932

Caleb R. St.-Jean

Reg. 73676

Patent attorney

The Law Office of Caleb St.-Jean

Chicago, IL · 60640

312-550-5018

David Russell Stacey

Reg. 33794

Patent attorney

Hoffman Estates, IL · 60169

847-571-7973

Theresa R. Stadheim

Reg. 67464

Patent attorney

Marshall, Gerstein & Borun LLP

Chicago, IL · 60606-6357

612-743-4498

Daniel A. Staley

Reg. 60415

Patent attorney

Caterpillar Inc.

Peoria, IL · 61629

309-675-2989

Colin J Stalter

Reg. 78221

Patent attorney

Gerasimow Law

Chicago, IL · 60654

815-298-0868

Erik J Stanek

Reg. 53633

Patent attorney

Glenview, IL · 60026

847-998-1295

Michael S Stanko

Reg. 63846

Patent agent

Chicago, IL · 60614

402-770-8655

Gregory E Stanton

Reg. 45127

Patent attorney

Lempia Summerfield Katz LLC

Chicago, IL · 60603

312-854-8389

James G Staples

Reg. 19013

Patent attorney

A Finkl and Sons CO

Chicago, IL · 60619

773-975-2235

Andrew C Stark

Reg. 65742

Patent attorney

U.S. Department of Energy

Lemont, IL · 60439

301-828-9521

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.