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 Fitzsimmons IP Law, Lewis Kohn & Fitzwilliam LLP, and Twelve Benefit Corporation.

Top cities in California

All practitioners in California

Todd E Fitzsimmons

Reg. 44683

Patent attorney

Fitzsimmons IP Law

Gardena, CA · 90248

213-500-1178

Timothy William Fitzwilliam

Reg. 46439

Patent attorney

Lewis Kohn & Fitzwilliam LLP

San Diego, CA · 92130

858-436-1332

Brian N Fiumara

Reg. 80815

Patent agent

San Diego, CA · 92101

702-467-2198

Ryan J. Flaherty

Reg. 75240

Patent agent

Twelve Benefit Corporation

Berkeley, CA · 94710

734-507-0109

Sean D Flaherty

Reg. 67325

Patent attorney

Gordon & Rees, LLP

San Diego, CA · 92101

619-230-7473

Terrence M Flaherty

Reg. 64022

Patent agent

Chevron Corporation

Richmond, CA · 94802

510-242-2489

Daniel L Flamm

Reg. 54100

Patent attorney

Microtechnology Law and Analyis

Walnut Creek, CA · 94596-5459

925-826-3113

Darrin M. Flanigan

Reg. 79719

Patent attorney

Gilead Sciences, Inc.

Foster City, CA · 94404

650-528-0835

Michael G Flanigan

Reg. 69805

Patent attorney

Venture Point Legal

San Francisco, CA · 94121-2819

650-418-1067

Jennifer A Fleischer

Reg. 69469

Patent attorney

BioTime, Inc.

Alameda, CA · 94501

510-521-3390

James Franklin Fleming

Reg. 57332

Patent attorney

Entralta P.C.

Thousand Oaks, CA · 91320

858-304-0202

Michelle Muller Fleming

Reg. 42913

Patent attorney

Santa Clara, CA · 95054

408-585-8977

William C Fleming

Reg. 39191

Patent attorney

Environmental Systems Research Institute, Inc.

Redlands, CA · 92373

909-793-2853 X4624

Veronica J Flesch

Reg. 80583

Patent agent

Xencor

Monrovia, CA · 91016

626-305-5900

Larry D Flesner

Reg. 37827

Patent agent

San Diego, CA · 92117-1904

858-273-8531

Karen E Flick

Reg. 44111

Patent agent

Talis Biomedical Corporation

Menlo Park, CA · 94025

650-433-3023

David L Fligor

Reg. 54784

Patent attorney

Fligor Tech Law Group

Los Altos, CA · 94022

415-310-8543

P. Matthew Flinders

Reg. 56148

Patent attorney

Roche Diagnostics Operations

Santa Clara, CA · 95050

617-699-3068

Andrew S. Flior

Reg. 65565

Patent attorney

Snell & Wilmer LLP

Costa Mesa, CA · 92626

714-427-7083

Scott A Florance

Reg. 47565

Patent attorney

Quinn, Emanuel, Urquhart, Oliver

Los Angeles, CA · 90017

213-443-3679

Eglia N Flores

Reg. 54103

Patent attorney

FACEBOOK, INC

Palo Alto, CA · 94304

650-543-7462

Brian H. Floyd

Reg. 75782

Patent agent

Power Integrations

San Jose, CA · 95138

408-414-9561

Jennifer A. Floyd

Reg. 72738

Patent agent

Wilson Sonsini Goodrich & Rosati

Sandiego, CA · 92130-3002

858-350-2267

Mark B Floyd

Reg. 41022

Patent agent

Los Gatos, CA · 95032

408-569-1967

David R. Flyer

Reg. 57480

Patent attorney

Flyer & Flyer, a Professional Law Corporation

Newport Beach, CA · 92660

949-622-8444

Brian J Flynn

Reg. 30380

Patent attorney

Sunnyvale, CA · 94088

408-469-5522

Brian Joseph Flynn

Reg. 78620

Patent attorney

Knobbe, Martens, Olson & Bear, LLP

Irvine, CA · 92614

858-707-4187

Elizabeth M Flynn

Reg. 67500

Patent agent

El Cerrito, CA · 94530

510-499-5220

Sherrie M Flynn

Reg. 62066

Patent attorney

Coleman & Horowitt, LLP

Fresno, CA · 93704

559-248-4820

Stephen B Flynn

Reg. 64143

Patent agent

Cupertino, CA · 95014

408-463-2489

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.