Connecticut

Patent attorneys in Connecticut

Connecticut hosts 744 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 Connecticut. 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 Cantor Colburn LLP, McCarter & English, LLP, and Ohlandt Greeley Ruggiero and Perle LLP.

Top cities in Connecticut

All practitioners in Connecticut

Frederick G Dean

Reg. 48212

Patent attorney

Ohlandt Greeley Ruggiero and Perle LLP

Stamford, CT · 06901

203-327-4500

J Robert Dean· Jr

Reg. 33490

Patent attorney

Ruggiero, McAllister & McMahon LLC

Stamford, CT · 06901

203-293-9140

Lisa Catherine DeCrescente

Reg. 76849

Patent agent

Hamden, CT · 06514

203-530-8116

Robert A DeGroot

Reg. 34316

Patent agent

Mystic, CT · 06355

860-536-4918

Cedric G DeLaCruz

Reg. 36498

Patent attorney

The Hartford

Hartford, CT · 06155

860-547-7483

Anthony Peter DeLio· II

Reg. 18729

Patent attorney

DeLio & Peterson, LLC

New Haven, CT · 06511

203-787-0595

Geoffrey Goddard Dellenbaugh

Reg. 26864

Patent attorney

McCormick, Paulding & Huber, LLP

Hartford, CT · 06103-3402

860-549-5290

Stephanie S. DelPonte

Reg. 75192

Patent attorney

Unilever

Trumbull, CT · 06611

475-239-6329

Bojuan Deng

Reg. 64512

Patent attorney

Henkel Corporation

Stamford, CT · 06902

475-299-9116

Sherri T Dente

Reg. 56896

Patent attorney

Wiggin and Dana LLP

New Haven, CT · 06508-1832

203-498-4440

Gerald L DePardo

Reg. 36121

Patent attorney

McCormick, Paulding & Huber

Hartford, CT · 06103

860-549-5290

Drew D DeRubeis

Reg. 78721

Patent agent

Zero Carbon Systems

Windsor, CT · 06095

203-767-7898

Barry Edwin Deutsch

Reg. 25328

Patent attorney

Canton, CT · 06019

860-965-4332

Mary Ellen M Devlin

Reg. 27928

Patent attorney

Boehringer Ingelheim Corporation

Ridgefield, CT · 06877

203-798-4866

Valerie T DiDamo

Reg. 43425

Patent attorney

Cytec Industries, Inc.

Stamford, CT · 06902

203-321-2919

Alyson J. DiLena

Reg. 67731

Patent attorney

St. Onge Steward Johnston & Reens LLC

Stamford, CT · 06905

203-324-6155

Michael P Dilworth

Reg. 37311

Patent attorney

Dilworth IP, LLC

Trumbull, CT · 06611

203-220-8496

Reid E. Dodge

Reg. 74499

Patent attorney

Mayborn Group

Stamford, CT · 06901

260-609-8053

John R Doherty

Reg. 19748

Patent attorney

Law Office of John R. Doherty

Stevenson, CT · 06491-0706

203-459-8701

Joanna M. Dombrowski

Reg. 62702

Patent attorney

Shelton, CT · 06484

860-480-1300

Ira S Dorman

Reg. 24469

Patent attorney

Law Office of Ira S Dorman

East Hartford, CT · 06108

806-528-0772

Erica G Dorsey

Reg. 52829

Patent attorney

Ruggiero McAllister & McMahon LLC

Stamford, CT · 06901

203-293-7431

Susan Kay Doughty

Reg. 43595

Patent attorney

Cantor Colburn LLP

Hartford, CT · 06103

860-286-2929

David Anthony Dow

Reg. 46124

Patent attorney

Boehringer Ingelheim Pharmacerticals, Inc.

Ridgefield, CT · 06877-0368

203-791-6214

Michael D Downs

Reg. 50252

Patent attorney

Downs IP Law LLC

Stamford, CT · 06901

203-998-0560

James P Doyle

Reg. 41717

Patent attorney

Old Greenwich, CT · 06870

401-595-2834

Daniel F Drexler

Reg. 47535

Patent attorney

Cantor Colburn LLP

Bloomfield, CT · 06002

860-286-2929

Joseph C. Drish

Reg. 66198

Patent attorney

McCarter & English, LLP

Hartford, CT · 06103

860-275-6746

Samuel J Du Boff

Reg. 25969

Patent attorney

Westport, CT · 06880

203-454-3474

Samantha E. R. Dundon

Reg. 83311

Patent agent

McCarter & English, LLP

Hartford, CT · 06103

860-275-6749

Common questions

Do I need a patent attorney based in Connecticut?

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 Connecticut-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 Connecticut?

744 active USPTO-registered patent practitioners list a Connecticut 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.