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 Van Pelt, Yi & James LLP, Townsend and Townsend and Crew LLP, and Sheppard, Mullin, Richter & Hampton LLP.

Top cities in California

All practitioners in California

Cassie Yin

Reg. 82571

Patent attorney

Van Pelt, Yi & James LLP

Los Altos, CA · 94022

408-207-4770

Jikai Yin

Reg. 83711

Patent agent

Foster City, CA · 94404

650-918-9826

Lu Yin

Reg. 60214

Patent attorney

Townsend and Townsend and Crew LLP

Palo Alto, CA · 94301

650-752-2436

Ronald Loh-Hwa Yin

Reg. 27607

Patent agent

Mountain View, CA · 94041-2577

650-969-6320

Shong Yin

Reg. 71577

Patent attorney

Sheppard, Mullin, Richter & Hampton LLP

Menlo Park, CA · 94025-4111

650-815-2622

Jiyuan H. Ying

Reg. 84439

Patent agent

San Francisco, CA · 94107

801-898-7573

Vincent J. Ying

Reg. 76065

Patent attorney

Skadden, Arps, Slate, Meagher & Flom LLP

Palo Alto, CA · 94301

650-470-3174

Donald Du Yip

Reg. 50465

Patent attorney

Yip & Associates Law Offices

San Gabriel, CA · 91775

626-698-0793

Philip S Yip

Reg. 37265

Patent attorney

Santa Clara, CA · 95051

408-649-1416

Vincent K Yip

Reg. 42245

Patent attorney

Nixon Peabody LLP

Los Angeles, CA · 90071

213-629-6196

Wai Tai L. Yip

Reg. 64995

Patent attorney

Nguyen & Yip, P.C.

Diamond Bar, CA · 91765

909-843-6522

Joshua C Yoburn

Reg. 64658

Patent agent

San Francisco, CA · 94122

415-377-8872

Gregory D. Yoder

Reg. 60994

Patent attorney

Law Office of Gregory Yoder

Mission Viejo, CA · 92691

949-334-7184

Toshiyuki Yokoi

Reg. 65348

Patent agent

Marina Del Rey, CA · 90292

310-880-0976

Brent T. Yonehara

Reg. 75928

Patent agent

Yonaxis, LLC

San Francisco, CA · 94105

415-294-1280

Stephanie A Yonker

Reg. 58528

Patent attorney

Alector, LLC

South San Francisco, CA · 94080

415-231-5660

Heejong Yoo

Reg. 63511

Patent attorney

Qualcomm Inc.

San Diego, CA · 92121

858-651-8186

Jason J Yoo

Reg. 59286

Patent attorney

TSMC Technology Inc.

San Jose, CA · 95134

408-678-2734

Michael D. Yoo

Reg. 72368

Patent attorney

Quinn Emanuel Urquhart & Sullivan, LLP

San Francisco, CA · 94111

415-875-6345

Rina L. Yoo

Reg. 71057

Patent attorney

Sylmar, CA · 91342

818-269-8187

Siho Yoo

Reg. 78634

Patent attorney

Vinson & Elkins, LLP

San Francisco, CA · 94105

415-979-6911

Chuhee M Yoon

Reg. 78001

Patent attorney

Cisco Systems Inc.

San Jose, CA · 95134

408-853-7260

Hanna H. Yoon

Reg. 72307

Patent attorney

Denali Therapeutics

South San Francisco, CA · 94080

650-866-8548

Hayan Yoon

Reg. 78318

Patent attorney

Fenwick & West LLP

Mountain View, CA · 94041

650-988-8500

Hee Jae J. Yoon

Reg. 75312

Patent attorney

Trojan Law Offices

Beverly Hills, CA · 90212

310-777-8399

Hee Sung Yoon

Reg. 57278

Patent agent

La Crescenta, CA · 91214

213-598-4531

Hyoungsoo Yoon

Reg. 57637

Patent agent

Sunnyvale, CA · 94087

408-309-8010

James Chung-Yul Yoon

Reg. 43297

Patent attorney

Wilson Sonsini Goodrich and Rosati

Palo Alto, CA · 94304

650-493-9300

Richard K Yoon

Reg. 42247

Patent attorney

Laguna Niguel, CA · 92677

818-350-3587

Seokhyun Yoon

Reg. 65103

Patent attorney

Samsung Research America

Mountain View, CA · 94043

408-320-9377

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.