The 45 largest companies in South San Francisco (2026 list)

#	Company	Industry	Headquarters	Employees	Founded
1	Genentech gene.com A cutting-edge science company passionate about finding innovative solutions for difficult-to-treat conditions, providing global access to life-changing medicines	Biotechnology Research	🇺🇸 South San Francisco	18,287	1976
2	Stripe stripe.com Financial infrastructure platform enabling businesses to accept payments, increase revenue, and explore new opportunities to grow in San Francisco and Dublin	Technology, Information and Internet	🇺🇸 South San Francisco	16,031	2010
3	Zipline zipline.com Designs, manufactures, and operates an automated delivery system serving tens of millions globally, transforming how goods move through clean, electric, instant logistics.	Transportation, Logistics, Supply Chain and Storage	🇺🇸 South San Francisco	1,867	2014
4	SAP SuccessFactors sap.com Provides cloud-based human capital management software applications for organizations, supporting core HR, payroll, talent, learning, compensation, and analytics with AI.	Software Development	🇺🇸 South San Francisco	1,518	2001
5	Twist Bioscience twistbioscience.com Company develops proprietary silicon-based manufacturing process for synthetic DNA, enabling cost-effective, rapid, precise, high-throughput DNA synthesis and sequencing for life science researchers across diverse fields.	Biotechnology Research	🇺🇸 South San Francisco	1,300	2013
6	Cytokinetics cytokinetics.com A biopharmaceutical company focused on developing muscle activators and inhibitors for treating diseases affecting muscle performance, recognized for workplace excellence	Biotechnology Research	🇺🇸 South San Francisco	781	1998
7	Aspiranet aspiranet.org A California nonprofit organization providing support and services to children, youth, and families for success in their homes, schools, and communities	Mental Health Care	🇺🇸 South San Francisco	723	1975
8	Veracyte, Inc.veracyte.com Developing genomic diagnostic tests to improve clinical outcomes by reducing inconclusive results and avoiding unnecessary surgeries for patients.	Biotechnology Research	🇺🇸 South San Francisco	716	2008
9	Color color.com Health technology company providing accessible, convenient, and cost-effective population-scale healthcare programs with a focus on cancer prevention, screening, and care management	Hospitals and Health Care	🇺🇸 South San Francisco	637	2014
10	Denali Therapeutics denalitherapeutics.com Company dedicated to defeating neurodegenerative diseases through innovative research, brain delivery engineering, biomarkers, and collaborative, impact-focused work environment	Biotechnology Research	🇺🇸 South San Francisco	582	2015
11	South San Francisco Unified School District ssfusd.org They are a leader in the green schools movement, providing diverse learning experiences for over 8,000 students with STEM and ethnic studies programs	Education	🇺🇸 South San Francisco	529	1913
12	Standard BioTools standardbio.com provides advanced proteomic and multi-omic technologies enabling researchers to uncover unique biological insights beyond conventional methods	Biotechnology Research	🇺🇸 South San Francisco	501	1999
13	Calico Life Sciences calicolabs.com Research and development focused on understanding human aging biology and creating therapeutics to extend healthy human lifespan and treat age-related diseases.	Biotechnology Research	🇺🇸 South San Francisco	479	2013
14	FDB (First Databank, Inc.)fdbhealth.com This company provides powerful drug knowledge to improve patient safety, operational efficiency, and health outcomes for healthcare organizations worldwide	Hospitals and Health Care	🇺🇸 South San Francisco	446	1978
15	City of South San Francisco ssfca.gov A vibrant city known as the Biotech Capital of the World, with a strong focus on innovation, community engagement, and high quality of life	Government Administration	🇺🇸 South San Francisco	428	1908
16	Blue Matter bluematterconsulting.com Specialized management consulting firm in the life sciences industry, providing strategic insights and innovative solutions to bio-pharmaceutical industry leaders worldwide	Business Consulting and Services	🇺🇸 South San Francisco	412	2012
17	ProcDNA procdna.com Analytics and software firm based in San Francisco specializing in accelerating commercial and clinical investments for clients in life sciences industries	Business Consulting and Services	🇺🇸 South San Francisco	403	2020
18	Health Plan of San Mateo (HPSM)hpsm.org A local non-profit health care plan providing coverage and a provider network for San Mateo County's under-insured population Serving over 145,000 residents	Hospitals and Health Care	🇺🇸 South San Francisco	345	1987
19	Cellares cellares.com Provides automated global cell therapy development and manufacturing services, enabling drug sponsors to scale and commercialize cell therapies for patient demand.	Pharmaceutical Manufacturing	🇺🇸 South San Francisco	314	2019
20	IDEAYA Biosciences ideayabio.com Oncology-focused precision medicine company in South San Francisco developing targeted therapeutics based on molecular diagnostics, with a primary focus on synthetic lethality	Biotechnology Research	🇺🇸 South San Francisco	266	2015
21	insitro insitro.com A data-driven drug discovery company using machine learning and high-throughput biology to create new medicines faster and cheaper	Biotechnology Research	🇺🇸 South San Francisco	255	2018
22	SSF Imported Auto Parts LLC ssfautoparts.com Supplier of OE-quality European auto parts, serving repair and collision specialists with comprehensive catalog and rapid service from multiple distribution centers nationwide	Motor Vehicle Manufacturing	🇺🇸 South San Francisco	244	1976
23	AKASA akasa.com AI-driven healthcare revenue cycle solutions provider, improving efficiency, reducing A/R days, and increasing revenue for hospitals and health systems	Software Development	🇺🇸 South San Francisco	240	2019
24	Lyell Immunopharma lyell.com Develops advanced CAR T-cell therapies for cancer patients, focusing on T-cells that resist exhaustion and have durable stemness for long-lasting clinical response.	Biotechnology Research	🇺🇸 South San Francisco	227	2018
25	Glydways glydways.com American transportation technology company specializing in affordable autonomous transportation with a focus on clean energy and high capacity needs	Urban Transit Services	🇺🇸 South San Francisco	222	2016
26	Sutro Biopharma, Inc.sutrobio.com A clinical-stage company focused on developing cancer therapeutics using innovative technology for improved patient experience, with a robust pipeline and industry collaborations	Biotechnology Research	🇺🇸 South San Francisco	210	2003
27	Onyx Pharmaceuticals, Inc., an Amgen subsidiary amgen.com A company specializing in developing and commercializing innovative cancer therapies to improve patients' lives, acquired by Amgen in 2013	Biotechnology Research	🇺🇸 South San Francisco	199	1991
28	Monogram Biosciences monogrambio.labcorp.com The company specializes in developing and commercializing innovative products for infectious diseases, cancer, and other serious illnesses, optimizing treatment regimens while reducing costs	Biotechnology Research	🇺🇸 South San Francisco	181	1995
29	Arsenal Biosciences, Inc.arsenalbio.com A clinical stage cell therapy company using CRISPR technology to create programmable treatments targeting solid tumors for enhanced efficacy and patient outcomes	Biotechnology Research	🇺🇸 South San Francisco	180	2019
30	Encoded Therapeutics Inc.encoded.com Encoded Therapeutics develops gene therapies targeting pediatric CNS disorders with cell-selective targeting, offering unprecedented gene specificity and broader therapeutic potential	Biotechnology Research	🇺🇸 South San Francisco	176	2014
31	Theravance Biopharma US, LLC theravance.com Specializing in respiratory and neurologic medications, we aim to make a difference in patients' lives by developing innovative treatments for unmet needs	Biotechnology Research	🇺🇸 South San Francisco	176	2014
32	Rock Medicine rockmed.org A security and investigations company located in San Francisco, California, specializing in providing services related to safety and investigations	Hospitals and Health Care	🇺🇸 South San Francisco	174	1973
33	Pliant Therapeutics pliantrx.com A late-stage biopharmaceutical company specializing in developing novel therapeutics for fibrotic diseases, with a focus on integrin biology and TGF-β modulation	Biotechnology Research	🇺🇸 South San Francisco	173	2015
34	Gino Morena Enterprises, LLC Specializing in US Military haircare for over 70 years, this company provides high-quality grooming products and services for military personnel	Consumer Services	🇺🇸 South San Francisco	171	1951
35	Cellworks cellworks.life Leader in Precision Drug Development and Personalized Therapy Biosimulation Predicts therapy response for patients using Computational Biology Model and biosimulation technology	Biotechnology Research	🇺🇸 South San Francisco	163	2005
36	Maze Therapeutics mazetx.com Maze Therapeutics integrates human genetics and functional genomics to develop lifesaving medicines based on genetic modifiers in severe diseases	Biotechnology Research	🇺🇸 South San Francisco	157	2018
37	Nkarta, Inc.nkartatx.com A biotech company developing allogeneic NK cell therapies using innovative cell engineering technologies to enhance tumor targeting and persistence	Biotechnology Research	🇺🇸 South San Francisco	156	2015
38	Alhuda School A community and Islamic school located in College Park, MD, providing education and resources for Muslim individuals and families	E-Learning Providers	🇺🇸 South San Francisco	146	n/a
39	Alector alector.com Innovative biotech company based in South San Francisco, dedicated to empowering the immune system to combat neurodegeneration and cancer through clinical trials	Biotechnology Research	🇺🇸 South San Francisco	140	2013
40	Tobi tobi.com Develops and sells Los Angeles inspired apparel through a proprietary technology platform, managing everything from design and production to online marketing.	Retail Apparel and Fashion	🇺🇸 South San Francisco	129	2007
41	Draeger's Markets draegers.com This company is a high-quality marketplace offering specialty food items, gourmet products, cooking classes, a restaurant, and exceptional customer service	Food and Beverage Services	🇺🇸 South San Francisco	113	1925
42	Calithera Biosciences calithera.com Clinical-stage biopharmaceutical company developing targeted therapies to starve tumor cells and boost immune-cell activity, improving treatment options for cancer patients	Pharmaceutical Manufacturing	🇺🇸 South San Francisco	25	2010
43	Openware openware.com Blockchain infrastructure development company specializing in next-gen Fintech solutions, creating safe and transparent financial ecosystems through Blockchain and DeFi integration	Software Development	🇺🇸 South San Francisco	23	2006
44	Selly Automotive CRM sellyautomotive.com CRM and internet lead management platform designed specifically for independent and BHPH dealerships to manage leads and customer follow-ups.	IT Services and IT Consulting	🇺🇸 South San Francisco	17	2014
45	GPToutreach gptoutreach.com It provides AI-powered outreach services, utilizing large language models for personalized prospecting, enhancing sales development through tailored communication strategies.	Information Services	🇺🇸 South San Francisco	8	n/a

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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