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 Irell and Manella LLP, Danisco US Inc., and Patane Gumberg Avila.

Top cities in California

All practitioners in California

Keith A Orso

Reg. 52084

Patent attorney

Irell and Manella LLP

Los Angeles, CA · 90067

310-277-1010

Monica A Ortel

Reg. 76192

Patent agent

San Jose, CA · 95117

408-838-1850

Anavelys Ortiz-Suarez

Reg. 63535

Patent agent

Danisco US Inc.

Palo Alto, CA · 94304-1013

650-846-7500

Harrison Y Osaki

Reg. 62766

Patent attorney

Patane Gumberg Avila

Salinas, CA · 93907

831-417-3602

Joshua N. Osborn

Reg. 77858

Patent attorney

SML Avvocati PC

Temecula, CA · 92589

951-315-2300

Heather Marie Osborne

Reg. 54352

Patent attorney

Poway, CA · 92064-2103

619-818-8473

Matthew F Oseas

Reg. 53423

Patent agent

Woodland Hills, CA · 91367

818-703-7617

Alexander S. Osterlind

Reg. 72571

Patent attorney

Los Angeles, CA · 90293

949-969-8864

Trenton B Ostler

Reg. 69045

Patent agent

Illumina Inc.

San Diego, CA · 92122

571-623-0106

Christopher D. Ostman

Reg. 76063

Patent attorney

Schwegman, Lundberg & Woessner, P.A.

San Jose, CA · 95113

408-278-4040

Todd A. Ostomel

Reg. 63426

Patent attorney

Squire Patton Boggs (US) LLP

Palo Alto, CA · 94304

650-843-3251

Ryan J Otis

Reg. 73075

Patent attorney

View, Inc.

Milpitas, CA · 95035

408-263-9200

Aisha O Otori

Reg. 80551

Patent attorney

Otori Law PC

Fresno, CA · 93727

858-220-4255

Katerina Otrubova

Reg. 76833

Patent agent

San Diego, CA · 92130

858-350-2216

Matthew J. Ott

Reg. 84268

Patent agent

Sheppard, Mullin, Richter & Hampton LLP

San Diego, CA · 92130

185-872-07496

James C Otteson

Reg. 40754

Patent attorney

Arnold & Porter LLP

Palo Alto, CA · 94304

650-798-2970

Erik A Otto

Reg. 54354

Patent agent

LifeScan INC

Milpitas, CA · 95035

408-956-4134

Susanne K Ottoboni

Reg. 68713

Patent agent

Belmont, CA · 94002

650-594-9311

Thomas B. Ottoboni

Reg. 64987

Patent agent

Belmont, CA · 94002

650-594-9311

Joshua D. Ottosen

Reg. 80423

Patent attorney

Aikin & Gallant, LLP

Los Altos, CA · 94022

650-741-0956

Philip Ou

Reg. 61059

Patent attorney

Fremont, CA · 94539

510-378-4224

Bernard V Ousley

Reg. 19055

Patent attorney

Corona, CA · 92880

951-268-6032

Daniel E Ovanezian

Reg. 41236

Patent attorney

Womble Bond Dickinson LLP

Palo Alto, CA · 94303

408-341-3040

Tyler J. Overall

Reg. 61978

Patent attorney

Qualcomm Incorporated

San Diego, CA · 92121

858-845-3786

Leslie B Overman

Reg. 48541

Patent attorney

The Law Office of Leslie B. Overman

San Diego, CA · 92110

858-754-8778

Melville Owen

Reg. 19819

Patent attorney

Owen Wickersham and Erickson PC

San Francisco, CA · 94105

415-882-3200

David R Owens

Reg. 40756

Patent attorney

Owens Law Firm, PC

San Jose, CA · 95113

408-298-8200

Howard V Owens

Reg. 58219

Patent agent

USDA, ARS, OTT-United States Department of Agriculture, Agricultural

Albany, CA · 94710

510-559-6067

Jonathan Ottly Owens

Reg. 37902

Patent attorney

Haverstock and Owens LLP

Sunnyvale, CA · 94086

408-530-9700

Ryan R Owens

Reg. 65729

Patent attorney

Spearhead Legal LLP

Newport Beach, CA · 92660-7426

949-409-8401

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.