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 Byers IP Law & Consulting, LifeScan, and Calyx Law.

Top cities in California

All practitioners in California

Stephen D. Byers

Reg. 76613

Patent attorney

Byers IP Law & Consulting

Goleta, CA · 93117

310-962-3546

Patricia A Byrd

Reg. 52680

Patent agent

LifeScan

Milpitas, CA · 95035

408-956-4420

Christopher Ryan Byrnes

Reg. 65354

Patent attorney

Calyx Law

San Francisco, CA · 94110

510-570-6157

Timothy D. Byron

Reg. 76023

Patent agent

O'Melveny + Myers LLP

San Francisco, CA · 94111

415-984-8727

Oswaldo C Caballero

Reg. 80850

Patent attorney

Electronic Arts, Inc.

Redwood City, CA · 94065

165-062-80279

Christian G Cabou

Reg. 35467

Patent attorney

Solana Beach, CA · 92075

858-900-1384

Colin G Cabral

Reg. 73952

Patent attorney

Proskauer Rose LLP

Los Angeles, CA · 90067

310-284-5611

Feb Cabrasawan

Reg. 51521

Patent attorney

IBM Corporation

San Jose, CA · 95120

408-927-1000

Michael J Cabrera

Reg. 80607

Patent agent

Manteca, CA · 95337

209-629-8023

Deborah L Cadena

Reg. 44048

Patent agent

Jones Day

San Diego, CA · 92121

858-314-1160

Penelope A Cadigan

Reg. 48764

Patent attorney

P.A. Cadigan

Capistrano Beach, CA · 92624-0356

415-308-3984

Felissa Hirsch Cagan

Reg. 35089

Patent attorney

Johnson and Johnson

Fremont, CA · 94555

510-248-2706

Oral Caglar

Reg. 44577

Patent attorney

The Walt Disney Company

Burbank, CA · 91521

818-560-4261

Joseph P Cahill

Reg. 51523

Patent agent

Ventura Botanical Gardens, Inc.

Ventura, CA · 93006

805-232-3113

Steven J Cahill

Reg. 44578

Patent attorney

InventIQ Legal LLP

Menlo Park, CA · 94026-0779

650-242-8300

Jingming Cai

Reg. 44579

Patent attorney

San Jose, CA · 95113

408-436-0789

Michelle Cai

Reg. 50599

Patent agent

McDermott, Will & Emery, LLP

Palo Alto, CA · 94304

650-813-5052

Yu Cai

Reg. 67910

Patent attorney

Fate Therapeutics

San Diego, CA · 92131

858-875-1837

Zhiwei Cai

Reg. 84691

Patent attorney

KPPB LLP

Pasadena, CA · 91105

949-288-0877

Justin T. Cain

Reg. 75404

Patent attorney

Illumina, Inc.

San Diego, CA · 92122

708-305-0112

David A Caine

Reg. 52683

Patent attorney

Arnold & Porter Kaye Scholer LLP

Palo Alto, CA · 94306-2112

650-319-4710

Yuridia Caire

Reg. 66949

Patent attorney

Kramer Levin Naftalis & Frankel LLP

Menlo Park, CA · 94025

650-752-1700

Austin T Cairns

Reg. 75991

Patent agent

Walnut, CA · 91789

657-231-2070

Belinda J Cairns

Reg. 63486

Patent agent

Los Altos, CA · 94022

650-255-5867

Nicholas Cairns

Reg. 64331

Patent agent

Los Altos, CA · 94022

650-255-5813

Triniti Calcote

Reg. 902993

Limited recognition

University of San Francisco School of Law

San Francisco, CA · 94117-1080

341-230-9931

Richard C Calderwood

Reg. 35468

Patent attorney

NVIDIA Corporation

Santa Clara, CA · 85050

503-313-4004

Kurt G Calia

Reg. 38702

Patent attorney

Covington & Burling LLP

Redwood Shores, CA · 94065

650-632-4717

Robert A Calico· III

Reg. 57938

Patent attorney

ARM, Inc.

San Jose, CA · 95134

408-576-1596

Eric A Caligiuri

Reg. 58121

Patent agent

San Diego, CA · 92130

858-356-9456

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.