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 Agilent Technologies, Inc., Midnight Cellars, and Cooley LLP.

Top cities in California

All practitioners in California

Daniel Hart

Reg. 40637

Patent attorney

Agilent Technologies, Inc.

Santa Clara, CA · 92051

858-866-6152

John M Hart

Reg. 66989

Patent attorney

Sunnyvale, CA · 94086

650-215-8676

Robert E Hartenberger

Reg. 22108

Patent attorney

Midnight Cellars

Paso Robles, CA · 93446

805-239-8964

Johannah L. Hartley

Reg. 66319

Patent attorney

Santa Barbara, CA · 93101

805-568-2967

Kenichi N Hartman

Reg. 68766

Patent agent

Cooley LLP

Palo Alto, CA · 94304

650-843-5227

Peter A. Hartman

Reg. 57549

Patent attorney

San Juan Capistrano, CA · 92675

949-864-6689

Clare Therese Hartnett

Reg. 35185

Patent attorney

Law Office of Clare Hartnett

Palo Alto, CA · 94302

650-328-6774

Michael David Hartogs

Reg. 36547

Patent attorney

San Diego, CA · 92130

858-259-7573

Arlen M Hartounian

Reg. 52997

Patent attorney

Apple, Inc.

Cupertono, CA · 9514

408-783-1802

J Elin Hartrum

Reg. 43663

Patent attorney

Gilead Sciences, Drive

Foster City, CA · 94404

650-522-1871

William H Hartwell

Reg. 70040

Patent attorney

Amgen Inc.

Thousand Oaks, CA · 91320-1789

608-709-6110

Trenton E. Hartzler

Reg. 77412

Patent attorney

Reuben Raucher & Blum

Los Angeles, CA · 90025

310-777-1990

Sean S. Harvey

Reg. 84476

Patent agent

Encinitas, CA · 92024

650-353-0431

Janet E Hasak

Reg. 28616

Patent attorney

Chico, CA · 95928

530-809-9056

Syed A Hasan

Reg. 41057

Patent attorney

LEWIS ROCA ROTHGERBER CHRISTIE LLP

Glendale, CA · 91203

626-795-9900

Erick K. Hasegawa

Reg. 69546

Patent attorney

Rivian Automotive, LLC

Irvine, CA · 92606

949-836-3469

Majid M Hashemi

Reg. 65805

Patent agent

San Jose, CA · 95160

408-483-8349

Daniel S. Hashimi

Reg. 68538

Patent attorney

Pasadena, CA · 91101

(62-6) -793-9364

Takashi Hashimoto

Reg. 47635

Patent attorney

TE Connectivity Corporation

Fremont, CA · 94555

650-361-5875

Judith A Hasko

Reg. 41819

Patent attorney

Latham & Watkins, LLP

Menlo Park, CA · 94025

650-463-3065

Averie K Hason

Reg. 57722

Patent attorney

Seagate Technology LLC

Fremont, CA · 94538

510-661-1000

Katherine D. Hasper

Reg. 75123

Patent attorney

Wilson Sonsini Goodrich & Rosati

Palo Alto, CA · 94304

650-849-3474

Michael T Hasper

Reg. 58934

Patent attorney

NVIDIA Corporation

Santa Clara, CA · 95050

408-486-2000

Saad K. Hassan

Reg. 70223

Patent attorney

Fenwick & West

Mountain View, CA · 94041

650-335-7182

Steve P Hassid

Reg. 46762

Patent attorney

Partners Law Group

Santa Monica, CA · 90403

310-922-2206

Evan L Hastings

Reg. 78745

Patent attorney

NIWC Pacific

San Diego, CA · 92125

602-717-6462

Ryan E Hatch

Reg. 55252

Patent attorney

Law Office of Ryan E. Hatch

Los Angeles, CA · 90066

310-279-5076

Raina Hatem

Reg. 902606

Limited recognition

University of San Francisco School of Law

San Francisco, CA · 94117-1080

650-302-8691

Cynthia D. Hathaway

Reg. 59735

Patent attorney

Global Patent Group Inc.

BURBANK, CA · 91506

877-812-8020

Benjamin W Hattenbach

Reg. 41820

Patent attorney

Irell and Manella, LLP

Los Angeles, CA · 90067

310-277-1010

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.