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 Nwamu, P.C., Neil K. Nydegger, Esq., and State of California Office of Administrative Hearings.

Top cities in California

All practitioners in California

Fidel D Nwamu

Reg. 46294

Patent attorney

Nwamu, P.C.

Oakland, CA · 94610

510-400-8890

Gregory W. Nyce

Reg. 75985

Patent agent

Pleasanton, CA · 94566

925-586-9947

Neil K Nydegger

Reg. 30202

Patent attorney

Neil K. Nydegger, Esq.

Rancho Santa Fe, CA · 92067

619-688-1300

Debra D Nye-Perkins

Reg. 48260

Patent attorney

State of California Office of Administrative Hearings

San Diego, CA · 92101

619-525-4475

Suiko Nyman

Reg. 48661

Patent attorney

Ambit Biosciences Corporation

San Diego, CA · 92121

858-334-2158

Frederick E. Nytko· III

Reg. 79772

Patent agent

Newark, CA · 94560

John P O'Banion

Reg. 33201

Patent attorney

O'Banion and Ritchey LLP

Sacramento, CA · 95814

916-498-1010

Christy M O'Berry

Reg. 64004

Patent attorney

Hermose Beach, CA · 90254

424-257-0692

Emily C O'Brien

Reg. 57251

Patent attorney

Google LLC.

South San Francisco, CA · 94080

415-513-2465

Kuwabo O'Brien

Reg. 78179

Patent agent

Goodwin Procter LLP

San Francisco, CA · 94105

415-733-6238

Robert A O'Brien

Reg. 48401

Patent attorney

American Canyon, CA · 94503

707-642-9505

Timothy J O'Brien

Reg. 68264

Patent attorney

RPX Corporation

San Francisco, CA · 94111

866-779-7641

Michael J O'Connell

Reg. 42950

Patent attorney

Innovation Counsel LLP

San Jose, CA · 95134

408-331-1675

Robert John O'Connell

Reg. 44265

Patent attorney

Dexcom, Inc

San Diego, CA · 92121

858-203-6054

Edward F O'Connor

Reg. 25903

Patent attorney

Encino, CA · 91316

949-291-2894

Ryan P. O'Connor

Reg. 60254

Patent agent

San Diego, CA · 92126

970-988-7752

John R O'Donnell

Reg. 76940

Patent attorney

Jones Day

Los Angeles, CA · 90017-2300

213-243-2155

Cynthia H O'Donohue

Reg. 44980

Patent agent

Applied Power Concepts, Inc.

Anaheim, CA · 92801

714-264-1411

John F O'Flaherty

Reg. 26319

Patent attorney

Alamo, CA · 94507

925-820-1383

Christopher F O'Hara

Reg. 63875

Patent attorney

Grover Beach, CA · 93483

559-355-8427

James K O'Hare

Reg. 56574

Patent attorney

QUALCOMM Incorporated

San Diego, CA · 92121

858-651-4186

Richard C O'Hare

Reg. 46211

Patent attorney

Carle, Mackie, Power & Ross LLP

Santa Rosa, CA · 95401

707-526-4200

P. J. Benedict O'Mahoney

Reg. 66494

Patent attorney

NetLawyers LLP

Foster City, CA · 94404

650-918-7714

Blake A O'Neill

Reg. 50190

Patent attorney

Palm Springs, CA · 92264

919-265-4021

Elizabeth M O'Neill

Reg. 42954

Patent agent

Elan Pharmacuticals

South San Francisco, CA · 94080

650-616-2690

James G O'Neill

Reg. 22858

Patent attorney

Klein, O'Neill & Singh, LLP

Irvine, CA · 92612

949-955-1920

Michael K O'Neill

Reg. 32622

Patent attorney

Venable LLP

San Francisco, CA · 94111

415-343-4515

Sean O'Neill

Reg. 45446

Patent attorney

NovaTech IP Law

San Clemente, CA · 92673

949-466-3860

Charles L O'Rourke

Reg. 26014

Patent attorney

Finnegan, Henderson, Farabow, Garrett & Dunner, LLP

Palo Alto, CA · 94304

650-849-6640

John F O'Rourke

Reg. 38985

Patent attorney

WHGC

Newport Beach, CA · 92660

949-833-8483

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.