California

Patent attorneys in California

California hosts 9,567 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 Knobbe, Martens, Olson & Bear LLP, SanDisk Corporation, and Harbor Freight Tools USA, Inc..

Top cities in California

All practitioners in California

Daniel P Custodio

Reg. 69855

Patent attorney

SanDisk Corporation

Milpitas, CA · 95035

408-801-7122

Jeffrey N Cutler

Reg. 35486

Patent attorney

Harbor Freight Tools USA, Inc.

Calabasas, CA · 91302

805-233-5172

Adrian R. Cyhan

Reg. 54576

Patent attorney

Stubbs Alderton & Markiles LLP

Sherman Oaks, CA · 91403

818-444-4554

Charles R Cypher

Reg. 41694

Patent attorney

Law Office of James R. Cypher

Oakland, CA · 94612

510-832-4111

James Robert Cypher

Reg. 22448

Patent attorney

Law Office Of James R. Cypher

Oakland, CA · 94612

510-832-4111

Logan Samson Cyr

Reg. 902908

Limited recognition

University of California, Los Angeles School of Law

Los Angeles, CA · 90095-1476

612-747-3303

Ashkon Cyrus

Reg. 69832

Patent agent

Select Patents

Marina Del Rey, CA · 90292

650-279-7846

James R Czaja

Reg. 63554

Patent attorney

SAP Labs

Palo Alto, CA · 94304

650-849-4192

Stephen C D'Amico

Reg. 46652

Patent attorney

AbbVie, Inc.

Irvine, CA · 92612

224-440-7242

Bron Erik D'Angelo

Reg. 64477

Patent attorney

Pettit Kohn Ingrassia & Lutz PC

Los Angeles, CA · 90045

424-702-1094

Chantal Morgan D'Apuzzo

Reg. 48825

Patent attorney

Stanford University

Stanford, CA · 94305-2038

650-723-9611

Christian D'Avignon-Aubut

Reg. 59995

Patent attorney

Carlsbad, CA · 92018

442-385-3581

Melanius D'Souza

Reg. 42458

Patent agent

San Dimas, CA · 91773

909-599-0801

Timothy P. Dabrowski

Reg. 83240

Patent attorney

Los Angeles, CA · 90067

480-559-3205

Louis Leon Dachs

Reg. 26858

Patent attorney

Pacific Palisades, CA · 90272

310-230-8872

Kariman H Dadbeh

Reg. 50946

Patent agent

Encinitas, CA · 92024

760-943-7032

Charles E Dadswell· Jr

Reg. 35851

Patent attorney

Illumina, Inc

San Diego, CA · 92122

858--20-2-4500

Nancy K Dahl

Reg. 33671

Patent attorney

Elcelyx Therapeutics, Inc

San Diego, CA · 92130

858-945-8719

John R Dahnad

Reg. 75816

Patent agent

Dana Legal Services

Menlo Park, CA · 94025

480-399-0176

Qian Dai

Reg. 61569

Patent attorney

Knobbe, Martens, Olson & Bear LLP

Irvine, CA · 92614

858-707-4000

Brandon P. Dailey

Reg. 78532

Patent agent

Emeryville, CA · 94608

248-310-1668

Derek C Dailey

Reg. 65562

Patent attorney

Knobbe, Martens, Olson & Bear LLP

San Diego, CA · 92130

858-707-4000

Jialing Xu Dailey

Reg. 69148

Patent attorney

San Jose, CA · 95118

408-439-0054

Anthony J Dain

Reg. 46651

Patent attorney

Procopio Cory Hargreaves & Savitch, LLP

San Diego, CA · 92101

619-238-1900

Brian J Daiuto

Reg. 38422

Patent attorney

Google LLC

Mountain View, CA · 94043

650-464-8722

Katricia Y. Dakin

Reg. 84697

Patent agent

Fremont, CA · 94539

510-358-6747

Lloyd E Dakin· Jr.

Reg. 38423

Patent attorney

NXP Semiconductors N.V.

Fremont, CA · 94537

510-509-4291

Jihad Dakkak

Reg. 76359

Patent attorney

Plumas Lake, CA · 95961

419-344-0706

Sona D Dalal

Reg. 50777

Patent attorney

Novel IP

Santa Ana, CA · 92701

949-795-2386

David P Dalke

Reg. 40980

Patent attorney

Winston & Strawn LLP

Los Angeles, CA · 90071

213-615-1700

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?

9,567 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.