# 30 leading research institutes in the Essonne department

Tamtam tracks 42 research institutes headquartered in the Essonne department. This list ranks the 30 largest by number of employees on LinkedIn, led by École Polytechnique, CentraleSupélec and ONERA - The French Aerospace Lab. Their median headcount is 225. Half of them were founded in 2003 or later. The most common headquarters are Palaiseau (16), Gif-sur-Yvette (8) and Orsay (6).

The research institutes in Essonne are predominantly higher education institutions and research services, with a strong focus on science, technology, and engineering. Many are large organizations, reflecting their role in national and international research. Notable examples include École Polytechnique, a leading French institution in science and technology; CentraleSupélec, providing higher education with a large student body; ONERA - The French Aerospace Lab, researching aerospace and defense challenges; and AgroParisTech, educating professionals in life and environmental sciences.

A clear pattern is the concentration of these institutes in Palaiseau and Gif-sur-Yvette, indicating a central hub for research and higher education in the Essonne department. The founding dates range from the 18th century to the 21st century, with a cluster of institutions founded in the 21st century.

🇫🇷 Essonne · 30 companies · Updated Nov 11, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [École Polytechnique](https://www.tamtam.ai/c/ecole-polytechnique) (polytechnique.edu)<br>Leading French institution offering top-level research, academic programs, and innovation in science and technology with a strong emphasis on excellence and humanist traditions | Research Services | 🇫🇷 Palaiseau | 4,377 | 1794 |
| 2 | [CentraleSupélec](https://www.tamtam.ai/c/centralesupelec) (centralesupelec.fr)<br>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. | Higher Education | 🇫🇷 Gif-sur-Yvette | 2,125 | 1829 |
| 3 | [ONERA - The French Aerospace Lab](https://www.tamtam.ai/c/onera-the-french-aerospace-lab) (onera.fr)<br>Researching future aerospace and defense challenges, contributing to industry competitiveness through expertise in all related disciplines and technologies. | Aviation and Aerospace Component Manufacturing | 🇫🇷 Palaiseau | 2,097 | 1946 |
| 4 | [AgroParisTech](https://www.tamtam.ai/c/agroparistech) (agroparistech.fr)<br>Educates professionals in life and environmental sciences, focusing on sustainable resource management, innovation, and bioeconomy through various academic programs. | Higher Education | 🇫🇷 Palaiseau | 1,093 | 2007 |
| 5 | [Télécom Paris](https://www.tamtam.ai/c/telecom-paris) (telecom-paris.fr)<br>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 | Higher Education | 🇫🇷 Palaiseau | 953 | 1878 |
| 6 | [ENSTA](https://www.tamtam.ai/c/ensta) (ensta.fr)<br>Leading public institution for higher education, research, and innovation. Offers engineering cycles, master's, doctorates, and specialized master's degrees for scientific and technical excellence. | Higher Education | 🇫🇷 Palaiseau | 916 | 1741 |
| 7 | [Paris-Sud University (Paris XI)](https://www.tamtam.ai/c/paris-sud-university-paris-xi) (universite-paris-saclay.fr)<br>A prestigious research university focused on understanding the world, student success, and meeting society's needs with top student integration into the workforce | Higher Education | 🇫🇷 Orsay | 910 | 1970 |
| 8 | [ENS Paris-Saclay](https://www.tamtam.ai/c/ens-paris-saclay) (ens-paris-saclay.fr)<br>Public institution providing high-level scientific and cultural education for research, teaching, and leadership roles in various sectors. | Higher Education | 🇫🇷 Gif-sur-Yvette | 847 | 1912 |
| 9 | [Institut Mines-Télécom (IMT)](https://www.tamtam.ai/c/institut-mines-telecom-imt) (imt.fr)<br>Leading public group of engineering and management graduate schools, higher education and research institution, with eight public and two affiliate schools. | Higher Education | 🇫🇷 Palaiseau | 474 | 2012 |
| 10 | [CEA-List](https://www.tamtam.ai/c/cea-list) (cea.fr)<br>A research institute specializing in digital technology, supporting companies in technological development through expertise, skills, patents, and collaborative projects | Research Services | 🇫🇷 Palaiseau | 456 | 2003 |
| 11 | [Synchrotron SOLEIL](https://www.tamtam.ai/c/synchrotron-soleil) (synchrotron-soleil.fr)<br>Third generation synchrotron providing advanced experimental facilities for material geometry and properties research, serving diverse scientific users worldwide. | Research Services | 🇫🇷 Gif-sur-Yvette | 403 | 2001 |
| 12 | [Institut Polytechnique de Paris](https://www.tamtam.ai/c/institut-polytechnique-de-paris) (ip-paris.fr)<br>Public higher education institution combining six top French engineering schools to deliver excellent training programs and cutting-edge research. | Higher Education | 🇫🇷 Palaiseau | 370 | 2019 |
| 13 | [Laboratoire de Physique des Plasmas](https://www.tamtam.ai/c/laboratoire-de-physique-des-plasmas) (polytechnique.fr)<br>Researching space, cold, and magnetic fusion plasmas, supporting major projects like ITER, and developing plasma technologies for various applications. | Research Services | 🇫🇷 Palaiseau | 339 | 2009 |
| 14 | [ENSAE Paris](https://www.tamtam.ai/c/ensae-paris) (ensae.fr)<br>A leading French institution in data science, statistics, economics, finance, and actuarial science with strong links to research and industry professionals | Higher Education | 🇫🇷 Palaiseau | 237 | 1945 |
| 15 | [C2N - Centre de Nanosciences et de Nanotechnologies](https://www.tamtam.ai/c/c2n-centre-de-nanosciences-et-de-nanotechnologies) (c2n.universite-paris-saclay.fr)<br>Research in material science, nanophotonics, nanoelectronics, nanobiotechnologies, microsystems, fundamental and applied nanotechnology science. | Research Services | 🇫🇷 Palaiseau | 225 | 2016 |
| 16 | [Institut d'Optique Graduate School](https://www.tamtam.ai/c/institut-d-optique-graduate-school) (institutoptique.fr)<br>Non-profit higher education institution specializing in optics and photonics research, offering accredited Masters and PhD programs, and facilitating technology transfers in the field | Higher Education | 🇫🇷 Palaiseau | 202 |  |
| 17 | [LISN - Laboratoire Interdisciplinaire des Sciences du Numérique](https://www.tamtam.ai/c/lisn-laboratoire-interdisciplinaire-des-sciences-du-numerique) (lisn.upsaclay.fr)<br>Researching core digital sciences and engineering, including AI, data science, human-machine interaction, language processing, and bioinformatics, with a focus on interdisciplinary approaches. | Research Services | 🇫🇷 Orsay | 163 | 2021 |
| 18 | [IRT SystemX](https://www.tamtam.ai/c/irt-systemx) (irt-systemx.fr)<br>Research institute focused on digital engineering for future systems, covering agile industry, autonomous transport, smart territories, and trusted internet solutions. | Research Services | 🇫🇷 Palaiseau | 142 | 2012 |
| 19 | [Laboratoire des Sciences du Climat et de l'Environnement](https://www.tamtam.ai/c/laboratoire-des-sciences-du-climat-et-de-l-environnement) (lsce.ipsl.fr)<br>A leading research institute focusing on understanding natural and human-induced climate and environmental variations through national and international projects | Research Services | 🇫🇷 Gif-sur-Yvette | 120 |  |
| 20 | [CEA ISAS](https://www.tamtam.ai/c/cea-isas) (cea.fr)<br>Develops predictive science for low-carbon energy through experimentation, modeling, and simulation across materials, chemistry, mechanics, thermohydraulics, neutronics, and analytical sciences. | Research Services | 🇫🇷 Gif-sur-Yvette | 115 | 2020 |
| 21 | [Institut Photovoltaïque d'Ile-de-France (IPVF)](https://www.tamtam.ai/c/institut-photovoltaique-d-ile-de-france-ipvf) (ipvf.fr)<br>Research and innovation services for photovoltaics, developing perovskites, III-V, tandem cells, BIPV, VIPV, agrivoltaics, IoT, and hydrogen technologies. | Research Services | 🇫🇷 Palaiseau | 103 | 2014 |
| 22 | [CREST - Center for Research in Economics and Statistics](https://www.tamtam.ai/c/crest-center-for-research-in-economics-and-statistics) (crest.science)<br>A research unit in France specializing in economics, statistics, sociology, and finance, with over 100 researchers and a focus on academic excellence | Research Services | 🇫🇷 Palaiseau | 89 |  |
| 23 | [Faculté de Pharmacie - Université Paris-Saclay](https://www.tamtam.ai/c/faculte-de-pharmacie-universite-paris-saclay) (pharmacie.universite-paris-saclay.fr)<br>Located in Orsay, the Faculty of Pharmacy is part of the University Paris-Saclay It is the largest academic research center in Pharmacy in France, offering exceptional training programs | Higher Education | 🇫🇷 Orsay | 84 |  |
| 24 | [Laboratory of Mechanics Paris-Saclay](https://www.tamtam.ai/c/laboratory-of-mechanics-paris-saclay) (lmps.ens-paris-saclay.fr)<br>Specializing in material and structural modeling, the company focuses on experimental mechanics, numerical simulation, and high-performance computing for research purposes | Research Services | 🇫🇷 Gif-sur-Yvette | 79 | 1975 |
| 25 | [Laboratoire Albert Fert](https://www.tamtam.ai/c/laboratoire-albert-fert) (laboratoire-albert-fert.cnrs-thales.fr)<br>The research laboratory specializes in various areas of condensed matter physics to develop applications and promote innovation in information and communication technologies | Research Services | 🇫🇷 Palaiseau | 71 | 1995 |
| 26 | [SATT Paris-Saclay](https://www.tamtam.ai/c/satt-paris-saclay) (satt-paris-saclay.fr)<br>Funding and supporting research valorization and technology transfer from Paris-Saclay academic institutions to market applications with significant investment. | Research Services | 🇫🇷 Orsay | 65 | 2014 |
| 27 | [CENTRE BORELLI](https://www.tamtam.ai/c/centre-borelli) (centreborelli.ens-paris-saclay.fr)<br>The Borelli Center brings together researchers in mathematics, computer science, and neuroscience focused on biomedical interfaces and industrial transfer | Research Services | 🇫🇷 Gif-sur-Yvette | 37 | 2020 |
| 28 | [CS³ - Centre Spatial de CentraleSupélec pour les CubeSats](https://www.tamtam.ai/c/cs-centre-spatial-de-centralesupelec-pour-les-cubesats) (facebook.com)<br>A student space center focused on developing CubeSat platforms for educational and research purposes | Defense and Space Manufacturing | 🇫🇷 Gif-sur-Yvette | 32 | 2018 |
| 29 | [IDRIS (CNRS)](https://www.tamtam.ai/c/idris-cnrs) (idris.fr)<br>National center providing high-performance computing and artificial intelligence resources and expertise to public and private scientific research communities. | IT System Operations and Maintenance | 🇫🇷 Orsay | 23 | 1993 |
| 30 | [Laboratoire de l'Accélérateur Linéaire](https://www.tamtam.ai/c/laboratoire-de-l-accelerateur-lineaire) (lal.in2p3.fr)<br>The company is involved in particle physics research, astroparticle physics, astrophysics, cosmology, accelerator and detector R&D with advanced techniques | Research Services | 🇫🇷 Orsay | 23 |  |

## 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 Nov 11, 2026.

## More company lists in the Essonne department

- [The largest companies in the Essonne department](https://www.tamtam.ai/l/largest-companies-essonne) (1,149)
- [Companies with in-house R&D in the Essonne department](https://www.tamtam.ai/l/r-and-d-companies-essonne) (198)
- [Multinational companies in the Essonne department](https://www.tamtam.ai/l/multinational-companies-essonne) (156)
- [Manufacturers in the Essonne department](https://www.tamtam.ai/l/manufacturers-essonne) (127)
- [Hardware manufacturers in the Essonne department](https://www.tamtam.ai/l/hardware-companies-essonne) (114)
- [Distributors and wholesalers in the Essonne department](https://www.tamtam.ai/l/distributors-and-wholesalers-essonne) (76)
- [IT Services and IT Consulting companies in the Essonne department](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-essonne) (70)
- [Professional services firms in the Essonne department](https://www.tamtam.ai/l/professional-services-firms-essonne) (68)
- [Public sector organisations in the Essonne department](https://www.tamtam.ai/l/public-sector-organisations-essonne) (66)
- [Aerospace and defence companies in the Essonne department](https://www.tamtam.ai/l/aerospace-and-defense-companies-essonne) (65)
- [IT services companies in the Essonne department](https://www.tamtam.ai/l/it-services-companies-essonne) (60)
- [Retail chains in the Essonne department](https://www.tamtam.ai/l/retail-chains-essonne) (59)
- [Construction companies in the Essonne department](https://www.tamtam.ai/l/construction-companies-essonne) (56)
- [Software Development companies in the Essonne department](https://www.tamtam.ai/l/software-development-companies-essonne) (51)
- [Pharmaceutical companies in the Essonne department](https://www.tamtam.ai/l/pharmaceutical-companies-essonne) (45)
- [Electronics and semiconductor companies in the Essonne department](https://www.tamtam.ai/l/electronics-companies-essonne) (44)
- [Events Services companies in the Essonne department](https://www.tamtam.ai/l/events-services-companies-essonne) (41)
- [SaaS companies in the Essonne department](https://www.tamtam.ai/l/saas-companies-essonne) (41)
- [Consulting firms in the Essonne department](https://www.tamtam.ai/l/consulting-firms-essonne) (40)
- [Family-owned companies in the Essonne department](https://www.tamtam.ai/l/family-owned-companies-essonne) (38)
- [Contract manufacturers in the Essonne department](https://www.tamtam.ai/l/contract-manufacturers-essonne) (35)
- [Research Services companies in the Essonne department](https://www.tamtam.ai/l/research-services-companies-essonne) (35)
- [Critical infrastructure operators in the Essonne department](https://www.tamtam.ai/l/critical-infrastructure-operators-essonne) (32)
- [Education providers in the Essonne department](https://www.tamtam.ai/l/education-companies-essonne) (30)

## The same list elsewhere in France

- [Research institutes in France](https://www.tamtam.ai/l/research-institutes-france) (965)
- [Research institutes in Île-de-France](https://www.tamtam.ai/l/research-institutes-ile-de-france) (329)
- [Research institutes in Auvergne-Rhône-Alpes](https://www.tamtam.ai/l/research-institutes-auvergne-rhone-alpes) (99)
- [Research institutes in Grand Est](https://www.tamtam.ai/l/research-institutes-grand-est) (97)
- [Research institutes in Occitanie](https://www.tamtam.ai/l/research-institutes-occitanie) (91)
- [Research institutes in Provence-Alpes-Côte d'Azur](https://www.tamtam.ai/l/research-institutes-provence-alpes-cote-dazur) (74)
- [Research institutes in Nouvelle-Aquitaine](https://www.tamtam.ai/l/research-institutes-nouvelle-aquitaine) (73)
- [Research institutes in the Bouches-du-Rhône department](https://www.tamtam.ai/l/research-institutes-bouches-du-rhone) (51)
- [Research institutes in the Haute-Garonne department](https://www.tamtam.ai/l/research-institutes-haute-garonne) (51)
- [Research institutes in Hauts-de-France](https://www.tamtam.ai/l/research-institutes-hauts-de-france) (49)
- [Research institutes in the Rhône department](https://www.tamtam.ai/l/research-institutes-rhone) (48)
- [Research institutes in Brittany](https://www.tamtam.ai/l/research-institutes-brittany) (36)
- [Research institutes in the Gironde department](https://www.tamtam.ai/l/research-institutes-gironde) (35)
- [Research institutes in the Nord department](https://www.tamtam.ai/l/research-institutes-nord) (33)
- [Research institutes in the Isère department](https://www.tamtam.ai/l/research-institutes-isere) (31)
- [Research institutes in Pays de la Loire](https://www.tamtam.ai/l/research-institutes-pays-de-la-loire) (31)
- [Research institutes in the Hérault department](https://www.tamtam.ai/l/research-institutes-herault) (29)
- [Research institutes in Normandy](https://www.tamtam.ai/l/research-institutes-normandy) (27)
- [Research institutes in Paris](https://www.tamtam.ai/l/research-institutes-paris) (200)
- [Research institutes in Toulouse](https://www.tamtam.ai/l/research-institutes-toulouse) (48)
- [Research institutes in Marseille](https://www.tamtam.ai/l/research-institutes-marseille) (41)
- [Research institutes in Montpellier](https://www.tamtam.ai/l/research-institutes-montpellier) (29)

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Source: https://www.tamtam.ai/l/research-institutes-essonne