California

Patent attorneys in California

California hosts 9,553 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 California. 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 Ross Patent Law Office, Gibson, Dunn & Crutcher LLP, and Ferguson Braswell Fraser Kubasta PC.

Top cities in California

All practitioners in California

Oren J. Rosenberg

Reg. 81694

Patent attorney

Irvine, CA · 92602

651-747-7957

Stuart M. Rosenberg

Reg. 60772

Patent attorney

Gibson, Dunn & Crutcher LLP

Palo Alto, CA · 94301-1744

650-849-5389

David A Rosenblitt

Reg. 69323

Patent agent

Ferguson Braswell Fraser Kubasta PC

Santa Clara, CA · 95054

408-540-3779

Jerald E Rosenblum

Reg. 19466

Patent attorney

Pillsbury Winthrop Shaw Pittman

Palo Alto, CA · 94304

650-233-4601

Dov Rosenfeld

Reg. 38687

Patent agent

Dov Rosenfeld dba Inventek

Oakland, CA · 94618

510-703-3526

Mitchell S Rosenfeld

Reg. 36258

Patent attorney

Rosenfeld Law Corporation

San Francisco, CA · 94123

415-928-3853

L Kenneth Rosenthal

Reg. 29697

Patent agent

Strategic Innovation Svcs

Chino Hills, CA · 91709

909-628-9890

Samuel J. Rosenthal

Reg. 76699

Patent agent

Schox Patent Group

San Francisco, CA · 94107

888-775-9990

David John Rosmann

Reg. 43059

Patent attorney

Irvine, CA · 92603

949--87-2-2423

Christopher L Ross

Reg. 60934

Patent attorney

Knobbe, Martens, Olson & Bear LLP

Irvine, CA · 92614

949-760-0404

Gary Edward Ross

Reg. 29431

Patent attorney

Pleasanton, CA · 94588

925-426-6816

Graham O Ross

Reg. 65274

Patent agent

Blue Sky Technical Advisers

Poway, CA · 92064

858-472-6943

John Riley Ross· III

Reg. 43060

Patent attorney

Ross Patent Law Office

Del Mar, CA · 92014

858-755-3122

John Riley Ross· Jr

Reg. 30530

Patent attorney

Ross Patent Law Office

Del Mar, CA · 92014

858-755-3122

Nathaniel F N Ross

Reg. 65659

Patent attorney

Adeli & Tollen LLP

Los Angeles, CA · 90025

310-442-9300 X306

Pepi Ross

Reg. 35339

Patent agent

Oakland, CA · 94618

510-655-6262

Cynthia C. Rosser

Reg. 59188

Patent attorney

Symantec Corporation

Mountain View, CA · 94043

650-527-1393

Jamie Lynn Rossi

Reg. 56875

Patent attorney

Zilka-Kotab P.C.

San Jose, CA · 95112

408-971-2573

Tatiana Rossin

Reg. 56833

Patent agent

Womble Bond Dickinson LLP

Palo Alto, CA · 94304

408-341-3000

Linda E Rost

Reg. 46234

Patent attorney

Genentech, Inc.

South San Francisco, CA · 94080

650-467-6838

Gary Rostomyan

Reg. 73442

Patent agent

San Diego, CA · 92128

323-545-8076

Gregory Lee Roth

Reg. 26224

Patent attorney

Law Offices of Gregory L Roth

La Palma, CA · 90623

714-723-6871

Steven Howard Roth

Reg. 28467

Patent attorney

Moraga, CA · 94556

925-388-9125

Michael I. Rothwell

Reg. 62298

Patent attorney

R4 Property Group, LLC

Los Angeles, CA · 90036

858-775-8695

Jonathan M. Rotter

Reg. 62857

Patent attorney

Los Angeles, CA · 90067

310-601-0335

Firoozeh Rouhanizadeh

Reg. 60865

Patent agent

Cisco Systems, Inc.

San Jose, CA · 95134

408-853-5416

Richard James Douglas Rouse

Reg. 43062

Patent agent

HTS Resources, LLC

San Diego, CA · 92117

619-846-8291

Thomas Richard Rouse

Reg. 40793

Patent attorney

San Diego, CA · 92130

858-449-0415

Norman Peter Rousseau

Reg. 20917

Patent attorney

Los Altos, CA · 94024

415-964-0374

Anthony J K Rovegno

Reg. 81788

Patent agent

Redlands, CA · 92374

847-707-3021

Common questions

Do I need a patent attorney based in California?

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 California-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 California?

9,553 active USPTO-registered patent practitioners list a California 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.