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 Kilpatrick Townsend & Stockton LLP, PatentMetrix,, and Lewis Anten A Professional Corp..

Top cities in California

All practitioners in California

David C. Annis

Reg. 54963

Patent attorney

Kilpatrick Townsend & Stockton LLP

San Francisco, CA · 94111

415-576-0200

Hazim Hamied Ansari

Reg. 40896

Patent agent

PatentMetrix,

Irvine, CA · 92604

949-233-5172

Edward O Ansell

Reg. 18374

Patent attorney

Claremont, CA · 91711

909-625-1244

Lewis Anten

Reg. 26604

Patent attorney

Lewis Anten A Professional Corp.

Encino, CA · 91436-1726

818-501-3535

Peter C Anthony

Reg. 68845

Patent agent

Menlo Park, CA · 94025

650-380-5716

William L Anthony· Jr

Reg. 24771

Patent attorney

Orrick Herrington and Sutcliffe LLP

Menlo Park, CA · 94025

650-614-7400

Robert C Antonio

Reg. 63136

Patent agent

Paradice and Li LLP

Campbell, CA · 95008

669-272-0767

Linda J Anvid

Reg. 52564

Patent attorney

Redwood City, CA · 94063

650-556-9708

Kazuo Aoki

Reg. 60618

Patent agent

Knobbe Martens Olson & Bear, LLP

Irvine, CA · 92614

949-760-0404

Jose J Aparicio

Reg. 48837

Patent attorney

Los Altos, CA · 94023

650-855-4165

Paul A Apffel

Reg. 35427

Patent attorney

Corte Madera, CA · 94925

415-250-0132

Randolph T Apple

Reg. 36429

Patent attorney

Kilpatrick Townsend & Stockton

Menlo Park, CA · 94025

650-326-2400

Sean K Apple

Reg. 74899

Patent attorney

Tyz Law Group PC

San Francisco, CA · 94111-4164

415-766-3530

Kathryn M Apsens

Reg. 80894

Patent attorney

Kilpatrick Townsend & Stockton, LLP

San Francisco, CA · 94111

415-273-4721

Mani Arabi

Reg. 75779

Patent attorney

Laguna Hills, CA · 92653

657-333-6264

Katsuhiro Arai

Reg. 43315

Patent attorney

Law Office of Katsuhiro Arai

Lake Forest, CA · 92630

949-457-8296

Chika Arakawa

Reg. 72375

Patent attorney

Morrison & Foerster, LLP

San Diego, CA · 92130

858-314-5467

Ionne Arakelyan

Reg. 83662

Patent agent

Burbank, CA · 91501

818-322-7727

Gene W Arant

Reg. 17936

Patent attorney

Sacramento, CA · 95670

916-858-8168

Martin Ravash Arastafar

Reg. 61904

Patent attorney

Veeva Systems Inc.

Pleasanton, CA · 94588

925-452-6500

Joan Obispo Arbolante

Reg. 58642

Patent attorney

Lowenstein Sandler LLP

Palo Alto, CA · 94301

650-433-5736

Roberto C Arbulu

Reg. 79590

Patent attorney

Glaser Weil Fink Howard Jordan & Shapiro LLP

San Diego, CA · 92101

619-762-5954

William C Archie· Jr

Reg. 45370

Patent agent

Archer Entertainment Law PC

Marina Del Rey, CA · 90292

310-439-3717

Andres Rafael Arciniega

Reg. 903202

Limited recognition

Loyola Law School

Los Angeles, CA · 90015

310-614-5964

Amelia Marie Ardito

Reg. 900764

Limited recognition

California Western School of Law

San Diego, CA · 92101-3046

858-295-9602

Bailey R. Arenberg

Reg. 82574

Patent attorney

Knobbe, Martens, Olson & Bear, LLP

Irvine, CA · 92614

949-760-0404

Matthew A Argenti

Reg. 61836

Patent attorney

Wilson Sonsini Goodrich & Rosati

Palo Alto, CA · 94304

650-493-9300

Alfredo J. Arguello

Reg. 66565

Patent attorney

Stanton, CA · 90680

310-709-6645

Sina Sean Aria

Reg. 69490

Patent attorney

O'Melveny & Myers LLP

Los Angeles, CA · 90071

213-430-7244

Kristen L Arienti

Reg. 67042

Patent agent

Johnson & Johnson

San Diego, CA · 92121

858-784-3205

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.