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 Workday Inc., Ishimaru & Associates, and Wison Sonini Goodrich & Rosati.

Top cities in California

All practitioners in California

David M Ishimaru

Reg. 47676

Patent agent

Workday Inc.

Plesanton, CA · 94588

408-204-6154

Mikio Ishimaru

Reg. 27449

Patent attorney

Ishimaru & Associates

San Jose, CA · 95110

408-738-0592

Anna M Ison

Reg. 75359

Patent attorney

Wison Sonini Goodrich & Rosati

Palo Alto, CA · 94304-1050

650-846-93196

Lisa L Ison

Reg. 64067

Patent agent

Intuitive Surgical, Inc.

San Jose, CA · 95125

408-523-2100

Ned A Israelsen

Reg. 29655

Patent agent

Escondido, CA · 92029

760-705-8450

James A Italia

Reg. 56549

Patent attorney

Italia IP

Burbank, CA · 91505

818-973-2720

Bruce S Itchkawitz

Reg. 47677

Patent attorney

Knobbe Martens Olson and Bear, LLP

Irvine, CA · 92614

949-760-0404

Brian C Ito

Reg. 66690

Patent attorney

Facebook, Inc.

Menlo Park, CA · 94025

650-308-7859

Richard Thomas Ito

Reg. 32242

Patent attorney

Nitto Denko Technical Corporation

Oceanside, CA · 92058

760-435-7006

Richard S. Ito

Reg. 61075

Patent attorney

Irvine, CA · 92618

949-300-3136

Yoshiko Ito

Reg. 70437

Patent agent

McDermott Will & Emery LLP

Irvine, CA · 92612-2565

959-757-6359

Mark John Itri

Reg. 36171

Patent attorney

BakerHostetler LLP

Costa Mesa, CA · 92626-7653

714-754-6600

Kirt L. Iverson

Reg. 62660

Patent attorney

Schwegman, Lundberg & Woessner, P.A.

San Jose, CA · 95113

408-660-2016

Glen E Ivey

Reg. 53058

Patent agent

Fort Bragg, CA · 95437

707-961-0652

Ryan K Iwahashi

Reg. 63378

Patent attorney

Cupertino, CA · 95014

408-482-2688

Scott M Iyama

Reg. 57920

Patent attorney

Orrick, Herrington & Sutcliffe LLP

Menlo Park, CA · 94025

650-614-7637

Izzat H Izzat

Reg. 69288

Patent agent

Oak Park, CA · 91377

661-857-4584

Jack I J'Maev

Reg. 45669

Patent attorney

Puritan Law, PC

Orange, CA · 92868

909-437-8390

Jill A Jablonowski

Reg. 71974

Patent agent

Johnson & Johnson

San Diego, CA · 92121

858-784-3210

Edward G Jablonski

Reg. 46070

Patent agent

Iris Molecular Diagnostics

Carlsbad, CA · 92011

760-438-99237604

David B. Jackrel

Reg. 76731

Patent agent

Jackrel Consulting Inc.

Pacifica, CA · 94044

650-208-8223

Blake W Jackson

Reg. 66272

Patent attorney

DLA Piper, LLP (US)

East Palo Alto, CA · 94303

650-833-2248

Emma G. Jackson

Reg. 83916

Patent agent

San Diego, CA · 92126

615-516-9871

Harold Leo Jackson

Reg. 17766

Patent attorney

Santa Ana, CA · 92705

714-832-2080

Jeffrey M Jackson

Reg. 60368

Patent agent

University of California at Santa Cruz

Santa Cruz, CA · 95064

831-459-3976

Juneko Catherine Jackson

Reg. 48870

Patent attorney

Intellectual Property Law GRP LLP

San Jose, CA · 95113

408-286-8933

Mark Leland Jackson

Reg. 42687

Patent attorney

Genentech, Inc.

South San Francisco, CA · 94080

650-225-3149

Spencer D Jackson

Reg. 57833

Patent attorney

Orrick Herrington & Sutcliffe LLP

Menlo Park, CA · 94025

650-614-7474

Christopher T. Jacob

Reg. 59938

Patent attorney

Celula, Inc

San Diego, CA · 92121

858-875-8816

Johanna L Jacob

Reg. 64298

Patent agent

ORRICK, HERRINGTON & SUTCLIFFE LLP

Los Angeles, CA · 90017-5855

213-629-2020

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.