This list features public sector organizations in the Essonne department. The companies are predominantly higher education institutions and research services, with a strong presence of organizations founded in the 18th and 19th centuries, indicating a long-standing tradition of academic and scientific excellence.
Notable organizations include École Polytechnique, a leading institution in science and technology, and CentraleSupélec, providing higher education. ONERA - The French Aerospace Lab focuses on aerospace research, while LFB develops medicinal products. TechnicAtome specializes in nuclear reactor design, and CENTRE HOSPITALIER SUD FRANCILIEN offers public healthcare. A significant cluster of these organizations, such as École Polytechnique, Télécom Paris, and ENSTA, are headquartered in Palaiseau.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
École Polytechniquepolytechnique.edu
Leading French institution offering top-level research, academic programs, and innovation in science and technology with a strong emphasis on excellence and humanist traditions |
4,377 | |||
| 2 |
LFBgroupe-lfb.com
Develops, manufactures, and markets medicinal products for serious, often rare diseases in Hemostasis, Immunology, and Intensive Care, with a focus on plasma-derived products and biotechnologies. |
2,733 | |||
| 3 |
CentraleSupéleccentralesupelec.fr
Provides higher education with 4,500 students across three campuses, 370 staff, 3 international schools, 5 associated labs, and partners with 176 universities and 140 companies. |
2,125 | |||
| 4 |
ONERA - The French Aerospace Labonera.fr
Researching future aerospace and defense challenges, contributing to industry competitiveness through expertise in all related disciplines and technologies. |
2,097 | |||
| 5 |
TechnicAtometechnicatome.com
Specialized in compact nuclear reactor design, construction, and maintenance for various sectors including naval propulsion, research, medicine, and energy |
1,467 | |||
| 6 |
CENTRE HOSPITALIER SUD FRANCILIENchsf.fr
Public healthcare institution serving one million people in southern Île-de-France, providing medical services and hospital care to the community. |
1,219 | |||
| 7 |
AgroParisTechagroparistech.fr
Educates professionals in life and environmental sciences, focusing on sustainable resource management, innovation, and bioeconomy through various academic programs. |
1,093 | |||
| 8 |
Département de l'Essonneessonne.fr
Region with major transport links, hosting research centers, universities, competitive industries, and offering a high quality natural living environment. |
1,072 | |||
| 9 |
Télécom Paristelecom-paris.fr
A leading educational institution in ICT, offering various programs in engineering, masters, and PhD, with a focus on innovation and entrepreneurship in the digital world |
953 | |||
| 10 | 916 | ||||
| 11 |
Paris-Sud University (Paris XI)universite-paris-saclay.fr
A prestigious research university focused on understanding the world, student success, and meeting society's needs with top student integration into the workforce |
910 | |||
| 12 |
ENS Paris-Saclayens-paris-saclay.fr
Public institution providing high-level scientific and cultural education for research, teaching, and leadership roles in various sectors. |
847 | |||
| 13 | 829 | ||||
| 14 |
Institut Mines-Télécom (IMT)imt.fr
Leading public group of engineering and management graduate schools, higher education and research institution, with eight public and two affiliate schools. |
474 | |||
| 15 | 456 | ||||
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| 16 |
Groupe hospitalier Nord-Essonnegh-nord-essonne.fr
Regional hospital network providing comprehensive medical services including emergency, maternity, pediatrics, surgery, psychiatry, and critical care with modern technical facilities. |
446 | |||
| 17 |
Ville de Massyville-massy.fr
City with dynamic living environment, excellent transport links, attracting residents and businesses, fostering multicultural community in Greater Paris area. |
443 | |||
| 18 |
Synchrotron SOLEILsynchrotron-soleil.fr
Third generation synchrotron providing advanced experimental facilities for material geometry and properties research, serving diverse scientific users worldwide. |
403 | |||
| 19 |
Institut Polytechnique de Parisip-paris.fr
Public higher education institution combining six top French engineering schools to deliver excellent training programs and cutting-edge research. |
370 | |||
| 20 |
Laboratoire de Physique des Plasmaspolytechnique.fr
Researching space, cold, and magnetic fusion plasmas, supporting major projects like ITER, and developing plasma technologies for various applications. |
339 | |||
| 21 |
Communauté Paris-Saclayparis-saclay.com
Intercommunal structure uniting 27 communes in Essonne, supporting nearly 300,000 residents in the Paris-Saclay area. |
254 | |||
| 22 |
ENSAE Parisensae.fr
A leading French institution in data science, statistics, economics, finance, and actuarial science with strong links to research and industry professionals |
237 | |||
| 23 |
C2N - Centre de Nanosciences et de Nanotechnologiesc2n.universite-paris-saclay.fr
Research in material science, nanophotonics, nanoelectronics, nanobiotechnologies, microsystems, fundamental and applied nanotechnology science. |
225 | |||
| 24 |
Ville de Grigny (91)grigny91.fr
A dynamic city in Essonne with ambitious urban, educational, ecological, and cultural projects led by Mayor Philippe Rio, focusing on sustainable development and community well-being |
219 | |||
| 25 |
IUT d'Orsayiut-orsay.universite-paris-saclay.fr
Official page of the University Institute of Technology (IUT) in Orsay, part of the University of Paris-Saclay |
216 | |||
| 26 |
Établissement public d'aménagement Paris-Saclayepa-paris-saclay.fr
The public establishment drives development in Paris-Saclay, a hub of science, technology, innovation, and urban planning, bolstered by top-tier academic and research institutions |
175 | |||
| 27 | 166 | ||||
| 28 |
LISN - Laboratoire Interdisciplinaire des Sciences du Numériquelisn.upsaclay.fr
Researching core digital sciences and engineering, including AI, data science, human-machine interaction, language processing, and bioinformatics, with a focus on interdisciplinary approaches. |
163 | |||
| 29 |
Ville de Brétigny-sur-Orgebretigny91.fr
Official page of a town located in Brétigny-sur-Orge Promoting a balance between city and countryside while being recognized as a sustainable and innovative community 🏡🌾🌳💡 |
155 | |||
| 30 |
Mairie de Verrières-le-Buissonverrieres-le-buisson.fr
Local government managing a community with rich heritage, green spaces, and a commitment to preserving and enhancing quality of life. |
142 | |||
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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 Nov 11, 2026.
More company lists in the Essonne department
- The largest companies in the Essonne department 1,149
- Companies with in-house R&D in the Essonne department 198
- Multinational companies in the Essonne department 156
- Manufacturers in the Essonne department 127
- Hardware manufacturers in the Essonne department 114
- Distributors and wholesalers in the Essonne department 76
- IT Services and IT Consulting companies in the Essonne department 70
- Professional services firms in the Essonne department 68
- Aerospace and defence companies in the Essonne department 65
- IT services companies in the Essonne department 60
- Retail chains in the Essonne department 59
- Construction companies in the Essonne department 56
- Software Development companies in the Essonne department 51
- Pharmaceutical companies in the Essonne department 45
- Electronics and semiconductor companies in the Essonne department 44
- Research institutes in the Essonne department 42
- Events Services companies in the Essonne department 41
- SaaS companies in the Essonne department 41
- Consulting firms in the Essonne department 40
- Family-owned companies in the Essonne department 38
- Contract manufacturers in the Essonne department 35
- Research Services companies in the Essonne department 35
- Critical infrastructure operators in the Essonne department 32
- Education providers in the Essonne department 30
The same list elsewhere in France
- Public sector organisations in France 4,006
- Public sector organisations in Île-de-France 993
- Public sector organisations in Auvergne-Rhône-Alpes 451
- Public sector organisations in Grand Est 425
- Public sector organisations in Provence-Alpes-Côte d'Azur 384
- Public sector organisations in Occitanie 317
- Public sector organisations in Nouvelle-Aquitaine 310
- Public sector organisations in Hauts-de-France 261
- Public sector organisations in Pays de la Loire 187
- Public sector organisations in the Bouches-du-Rhône department 183
- Public sector organisations in Normandy 166
- Public sector organisations in Brittany 165
- Public sector organisations in the Nord department 135
- Public sector organisations in Bourgogne-Franche-Comté 130
- Public sector organisations in Centre-Val de Loire 121
- Public sector organisations in the Rhône department 120
- Public sector organisations in the Haute-Garonne department 111
- Public sector organisations in the Gironde department 109
- Public sector organisations in the Hauts-de-Seine department 96
- Public sector organisations in the Seine-Saint-Denis department 91
- Public sector organisations in the Loire-Atlantique department 82
- Public sector organisations in Paris 460
- Public sector organisations in Marseille 103
- Public sector organisations in Toulouse 83