The companies listed are research services providers in Essonne. They are primarily large research institutions and laboratories, many of which are publicly funded or affiliated with academic bodies. Examples include École Polytechnique, a leading French institution for research and academic programs in science and technology, and HORIBA for Materials, which focuses on researching and developing new materials. CEA-List specializes in digital technology, supporting companies through expertise and collaborative projects, while Synchrotron SOLEIL provides advanced experimental facilities for material research.
These organizations are concentrated in a few key locations within Essonne. Palaiseau hosts a significant number of these entities, including Laboratoire de Physique des Plasmas, which researches space and fusion plasmas, and C2N - Centre de Nanosciences et de Nanotechnologies, dedicated to material science and nanotechnology. This geographical clustering suggests a regional hub for scientific and technological research activities.
| # | 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 |
HORIBA for Materialshoriba.com
Researching, developing new materials, improving manufacturing, and implementing recycling solutions for sustainability across the material supply chain. |
1,053 | |||
| 3 | 456 | ||||
| 4 |
Synchrotron SOLEILsynchrotron-soleil.fr
Third generation synchrotron providing advanced experimental facilities for material geometry and properties research, serving diverse scientific users worldwide. |
403 | |||
| 5 |
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 | |||
| 6 |
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 | |||
| 7 |
IJCLabijclab.in2p3.fr
A leading physics research laboratory focused on the physics of astroparticles, energy, environment, and high-energy particles, with impressive scientific departments and technological capabilities |
171 | |||
| 8 |
CNRS à Paris-Saclayiledefrance-gif.cnrs.fr
A leading public research institution in Paris-Saclay, conducting fundamental research with societal, industrial, environmental applications through the work of 3300 scientists |
165 | |||
| 9 |
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 | |||
| 10 |
IRT SystemXirt-systemx.fr
Research institute focused on digital engineering for future systems, covering agile industry, autonomous transport, smart territories, and trusted internet solutions. |
142 | |||
| 11 |
Laboratoire des Sciences du Climat et de l'Environnementlsce.ipsl.fr
A leading research institute focusing on understanding natural and human-induced climate and environmental variations through national and international projects |
120 | |||
| 12 | 115 | ||||
| 13 |
Institut Photovoltaïque d'Ile-de-France (IPVF)ipvf.fr
Research and innovation services for photovoltaics, developing perovskites, III-V, tandem cells, BIPV, VIPV, agrivoltaics, IoT, and hydrogen technologies. |
103 | |||
| 14 |
CREST - Center for Research in Economics and Statisticscrest.science
A research unit in France specializing in economics, statistics, sociology, and finance, with over 100 researchers and a focus on academic excellence |
89 | |||
| 15 |
CERC (Cardiovascular European Research Center)cerc-europe.org
A leading European CRO founded by experienced physicians, specializing in clinical research, innovative techniques, and supporting young scientific leaders globally |
84 | |||
Want more companies than this list?This page shows the largest ones only. Connect to Tamtam to see every company that matches, filter by size, industry or growth, and reach their decision-makers. | |||||
| 16 |
Laboratory of Mechanics Paris-Saclaylmps.ens-paris-saclay.fr
Specializing in material and structural modeling, the company focuses on experimental mechanics, numerical simulation, and high-performance computing for research purposes |
79 | |||
| 17 |
Laboratoire Albert Fertlaboratoire-albert-fert.cnrs-thales.fr
The research laboratory specializes in various areas of condensed matter physics to develop applications and promote innovation in information and communication technologies |
71 | |||
| 18 |
SATT Paris-Saclaysatt-paris-saclay.fr
Funding and supporting research valorization and technology transfer from Paris-Saclay academic institutions to market applications with significant investment. |
65 | |||
| 19 | 60 | ||||
| 20 |
TECHNOSOL - Groupe Gengistechnosol-gengis.fr
TECHNOSOL is a geotechnical engineering firm part of GENGIS Group, specializing in geosciences and structures, with a team of 25+ engineers and 90 employees |
57 | |||
| 21 |
CENTRE BORELLIcentreborelli.ens-paris-saclay.fr
The Borelli Center brings together researchers in mathematics, computer science, and neuroscience focused on biomedical interfaces and industrial transfer |
37 | |||
| 22 |
Eurofins BIO-ECbio-ec.fr
Specializing in evaluating cosmetic, dermatological products, medical devices, and supplements through ex vivo and in vivo studies, absorption analysis, spectroscopy, and Cosmetogenomics Contact for personalized studies |
33 | |||
| 23 | 
LFB-BIOTECHNOLOGIES
LFB-BIOTECHNOLOGIES is a research company in France specializing in biotechnology, located in ZA DE COURTABOEUF LES ULIS |
26 | |||
| 24 |
Laboratoire de l'Accélérateur Linéairelal.in2p3.fr
The company is involved in particle physics research, astroparticle physics, astrophysics, cosmology, accelerator and detector R&D with advanced techniques |
23 | |||
| 25 |
Hi! PARIS Center - AI for Science, Business & Societyhi-paris.fr
An interdisciplinary center focused on AI and Data Science, partnering with leading organizations to address challenges of technological transformation for society and businesses |
19 | |||
| 26 |
EUROFLUX SASeuroflux.fr
Specializing in designing and installing clean rooms and equipment for aerobiological contamination control, such as unidirectional airflow systems and air showers |
18 | |||
| 27 |
Datastormdatastorm.fr
Datastorm offers data expertise and services to businesses and public organizations, combining data scientists and researchers from top institutions |
15 | |||
| 28 | 7 | ||||
| 29 |
Cell Environmentcell-environment.com
Precisely analyzing repetitive sequences and detecting chromosomal aberrations for precision medicine, diagnostics, and measuring cellular quality and aging across various fields. |
6 | |||
| 30 |
CRESP - CH MANHÈScresp-manhes.fr
The company is a Research Cell focused on paramedical care and health prevention, aiming to improve patient care and public health outcomes |
5 | |||
Turn this list into pipeline
Tamtam finds the decision-makers at every company on a list like this one, with verified emails, phone numbers and the buying signals that tell you when to reach out.
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 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
- Public sector organisations in the Essonne department 66
- 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
- Critical infrastructure operators in the Essonne department 32
- Education providers in the Essonne department 30
The same list elsewhere in France
- Research Services companies in France 745
- Research Services companies in Île-de-France 268
- Research Services companies in Auvergne-Rhône-Alpes 95
- Research Services companies in Provence-Alpes-Côte d'Azur 78
- Research Services companies in Occitanie 63
- Research Services companies in Grand Est 60
- Research Services companies in the Rhône department 49
- Research Services companies in Nouvelle-Aquitaine 48
- Research Services companies in the Bouches-du-Rhône department 47
- Research Services companies in the Haute-Garonne department 30
- Research Services companies in Brittany 29
- Research Services companies in the Isère department 29
- Research Services companies in the Gironde department 28
- Research Services companies in Hauts-de-France 27
- Research Services companies in Paris 148
- Research Services companies in Marseille 33