| # | Company | Employees |
|---|---|---|
| 1 |
Lawrence Livermore National Laboratoryllnl.gov
Development and application of advanced science, technology, and engineering to enhance national security, counterterrorism, defense, energy, and environmental challenges. |
9,546 |
| 2 |
FormFactor Inc.formfactor.com
A provider of test and measurement technologies for semiconductor companies, helping optimize performance, advance yield knowledge, and accelerate profitability throughout IC life cycle |
1,790 |
| 3 |
Topcon Positioning Systemstopconpositioning.com
Leading manufacturer for construction, geospatial, and agriculture markets, creating technology improving workflows. Also, global leader in positioning and ophthalmic diagnostic technologies. |
1,648 |
| 4 |
Kineticsexentec.net
A full-service process and mechanical contractor specializing in design and installation of systems for technology-driven markets, with global support and focus on safety and customer service |
1,014 |
| 5 |
McGrath RentCorpmgrc.com
A successful company with over $734 million in annual revenue, 1,200+ employees, and a strong company culture, seeking innovative individuals to join their team |
990 |
| 6 |
Las Positas Collegelaspositascollege.edu
Commitment to student success through academic transfer, career training, certification programs, and skill development, promoting equity and educational excellence on a vibrant campus |
715 |
| 7 |
Ferrotecferrotec.com
Global leader in advanced technology solutions, manufacturing materials, components, and assembly solutions for various industries worldwide Headquartered in Tokyo, Japan |
636 |
| 8 |
GILLIGgillig.com
Leading manufacturer of heavy-duty transit buses in the United States, offering clean energy propulsion systems built in California for public transportation. |
623 |
| 9 |
NORCAL Ambulancenorcalambulance.com
A leading medical transportation provider in Northern California, offering critical and routine transport services with a dedicated team focusing on customer service and patient care |
502 |
| 10 |
uCertifyucertify.com
An e-learning platform focused on interactive and hands-on learning, offering courses with test preparation for industry certifications |
473 |
| 11 |
Restoration Management Companyrmc.com
A full-service cleaning and restoration company offering emergency services 24/7 Certified technicians specialize in water, fire, mold, and sewage damage restoration |
468 |
| 12 |
Individual Softwareindividualsoftware.com
A leading developer of award-winning education, business, and personal productivity software for consumers, schools, businesses, and government since 1981 |
422 |
| 13 |
City of Livermorelivermoreca.gov
A historic California wine region with award-winning wineries, vibrant arts culture, and renowned science centers, striving to create a welcoming community for all |
379 |
| 14 |
Mobile Modular Management Corporationmobilemodular.com
A division of McGrath RentCorp, Mobile Modular provides high-quality modular buildings and portable classrooms for rent, lease, or purchase, prioritizing customer satisfaction |
338 |
| 15 |
Monarchmonarchtractor.com
Monarch leads in digital farming transformation with smart electric tractors, sustainable solutions, and data-driven insights to enhance farm productivity worldwide |
204 |
| 16 |
Wente Vineyardswentevineyards.com
An iconic, family-owned winery founded in 1883, with 3,000 acres of vineyards producing fine wines distributed worldwide and committed to sustainable practices |
200 |
| 17 |
AERaerworldwide.com
AER is a digital transformation company specializing in IT asset management, recycling, and value recovery, with global operations and certifications |
174 |
| 18 |
Retail Merchandising Solutions Inc.rmsicorp.com
The company offers strategy, merchandising, logistics, and reporting services, helping clients maximize efficiency and achieve their goals in retail |
166 |
| 19 |
JacketBack Embroideryjacketback.com
A leading provider of high school letter jackets specializing in custom embroidery and tackle twill designs, with a focus on fundraising programs for booster clubs |
160 |
| 20 |
HomeSite Services, Inc.homesiteservices.net
Residential, commercial, and retail services company offering superior work, quality products, and unbeatable customer service in interior design, flooring, and cabinetry |
149 |
| 21 |
MGT (formerly AMS.NET)mgt.us
An innovative technology solution provider delivering comprehensive services to education, local government, and businesses, now part of a firm focusing on public sector management |
149 |
| 22 |
Mancini's Sleepworldsleepworld.com
Providing Californians with the ideal mattresses and furniture for quality sleep and comfortable living for over 50 years Offering multiple locations |
148 |
| 23 |
Architectural Glass & Aluminumaga-ca.com
A company providing architectural glass and aluminum services in the Western United States, specializing in monumental projects for owners, architects, and contractors |
146 |
| 24 |
Powermatic Associatespowermatic.net
Specializing in factory automation solutions, providing top customer service, on-time delivery, and cutting-edge products in sensor, motion control, and machine control industries |
87 |
| 25 |
Modus Advanced, Inc.modusadvanced.com
A diversified company specializing in high-performance materials for OEMs, offering solutions in EMI shielding, gaskets, rubber molding, and thermal interface materials |
62 |
| 26 |
SANGRAF Internationalsangrafintl.com
Global manufacturer of premium graphite electrodes for steel industry, offering lean supply chain solutions and dedicated service teams for cost-effective, optimized electric arc furnaces |
44 |
| 27 |
TECO Technologytecotechnology.com
A longstanding company specializing in fluid & motion control products, offering services to enhance efficiency, reduce risk, and improve quality for clients |
39 |
| 28 |
Teqtron Inc.teqtron.com
TeqTron specializes in digital transformation, middleware integration, PLM, ERP implementation, and cloud integration services, focusing on automation and quality solutions |
37 |
| 29 |
Story Coffee Companystorycoffee.co
A cafe that opens daily to provide customers with a welcoming atmosphere and delicious coffee, aiming to brighten their days |
14 |
| 30 |
Mission Trading Company (MTC Parts)mtcparts.com
A global leader in manufacturing and importing high-quality aftermarket automotive parts from around the world, specializing in engine, suspension, electrical, and rubber components |
14 |
| 31 |
Terrill Transportation Incterrilltrans.com
A northern California trucking company specializing in full loads and LTL shipments, operating organic and Sqf storage facilities, with a fleet servicing the Continental 48 States |
12 |
| 32 |
Altamont Manufacturing, Inc.altamontmfg.com
Specializing in precision CNC machining, welding, and fabrication services, the company provides high-quality manufacturing solutions for various industries |
10 |
| 33 |
Forward Acceleratorforwardaccelerator.com
A startup accelerator and fund providing coaching, investment, and networking opportunities to help startups succeed in today's competitive environment |
3 |
| 34 |
AMERICAN INDUSTRIAL EQUIPMENT, LLCaiesac.com.pe
A software company located in Livermore, California, specializing in industrial equipment technology and solutions |
3 |
| 35 |
Creativegeeks IT solutions Private Limitedcreativegeeksit.com
Global software development and IT consulting firm offering various software solutions, web portals, talent on-demand, and workforce solutions to help clients achieve business objectives |
2 |
| 36 |
Ware-Portware-port.com
A 3PL company specializing in e-commerce fulfillment, warehouse logistics, and middle-to-last mile delivery services, redefining warehousing operations |
2 |
Turn this list into pipeline
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How this list is built
Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Oct 24, 2026.
The same list elsewhere in United States
- The largest companies in the United States 91,669
- The largest companies in California 12,813
- The largest companies in New York State 10,485
- The largest companies in Texas 8,086
- The largest companies in Florida 4,945
- The largest companies in Illinois 4,175
- The largest companies in Pennsylvania 3,110
- The largest companies in Massachusetts 3,093
- The largest companies in Georgia 2,632
- The largest companies in Ohio 2,618
- The largest companies in New Jersey 2,569
- The largest companies in Virginia 2,503
- The largest companies in Michigan 2,346
- The largest companies in North Carolina 2,174
- The largest companies in Alabama 1,806
- The largest companies in Washington State 1,785
- The largest companies in Colorado 1,774
- The largest companies in Minnesota 1,700
- The largest companies in Maryland 1,527
- The largest companies in Wisconsin 1,482
- The largest companies in New York 6,920
- The largest companies in San Francisco 2,030
- The largest companies in Houston 1,791
- The largest companies in Chicago 1,668