# The 30 largest public sector organisations in the Yvelines department

Tamtam tracks 65 public sector organisations headquartered in the Yvelines department. This list ranks the 30 largest by number of employees on LinkedIn, led by Département des Yvelines, Académie de Versailles and UVSQ Université de Versailles Saint-Quentin-en-Yvelines. Their median headcount is 324. Half of them were founded in 1972 or later. The most common headquarters are Versailles (18) and Plaisir (3).

These public sector organizations in Yvelines are primarily involved in government administration, education, healthcare, and cultural heritage. They range from large departmental bodies like the Département des Yvelines, which provides social support and education, to specialized institutions such as the Château de Versailles, maintaining cultural heritage. Mid-sized entities like UVSQ Université de Versailles Saint-Quentin-en-Yvelines focus on higher education and research, while SDIS 78 manages fire and rescue services.

A notable pattern among these organizations is their strong concentration in Versailles, which serves as the headquarters for many, including the Académie de Versailles, overseeing education, and the Ville de Versailles itself. Other significant entities like Hôpital de Poissy-Saint-Germain-en-Laye and Pôle Emploi are based in nearby towns such as Poissy and Plaisir, indicating a regional distribution of essential public services.

🇫🇷 Yvelines · 30 companies · Updated Nov 12, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Département des Yvelines](https://www.tamtam.ai/c/departement-des-yvelines) (yvelines.fr)<br>Local government providing social support, education, mobility, and territorial development services to improve daily life for residents. | Government Administration | 🇫🇷 Versailles | 4,000 | 1964 |
| 2 | [Académie de Versailles](https://www.tamtam.ai/c/academie-de-versailles) (ac-versailles.fr)<br>The company oversees education in four departments, serving 11 million students and managing 90,000 employees in various roles | Primary and Secondary Education | 🇫🇷 Versailles | 2,769 | 1972 |
| 3 | [UVSQ Université de Versailles Saint-Quentin-en-Yvelines](https://www.tamtam.ai/c/uvsq-universite-de-versailles-saint-quentin-en-yvelines) (uvsq.fr)<br>Provides diverse higher education, conducts innovative research across various fields, and fosters technological advancements with strong industry and international partnerships. | Research Services | 🇫🇷 Versailles | 2,170 | 1991 |
| 4 | [SDIS 78](https://www.tamtam.ai/c/sdis-78) (sdis78.fr)<br>Public establishment managing fire and rescue services in Yvelines, under mayors and prefects. Responsible for operations, personnel, and equipment. | Government Administration | 🇫🇷 Versailles | 1,061 | 1996 |
| 5 | [Service d’infrastructure de la Défense](https://www.tamtam.ai/c/service-d-infrastructure-de-la-defense) (defense.gouv.fr)<br>Manages, builds, and maintains the French Ministry of Armed Forces' real estate, ensuring infrastructure support and energy control for military operations domestically and abroad. | Construction | 🇫🇷 Versailles | 850 | 2005 |
| 6 | [Ville de Versailles](https://www.tamtam.ai/c/ville-de-versailles) (versailles.fr)<br>A historic city known for its palace and gardens, offering a vibrant local economy, employment opportunities in various fields, and a high quality of life | Government Administration | 🇫🇷 Versailles | 757 |  |
| 7 | [Château de Versailles](https://www.tamtam.ai/c/chateau-de-versailles) (chateauversailles.fr)<br>The company is a public institution maintaining and showcasing cultural heritage like the Versailles Palace, Trianon, gardens, and Marly domain They collaborate with various organizations | Museums, Historical Sites, and Zoos | 🇫🇷 Versailles | 732 | 1623 |
| 8 | [Hôpital de Poissy-Saint-Germain-en-Laye](https://www.tamtam.ai/c/hopital-de-poissy-saint-germain-en-laye) (ghtyvelinesnord.fr)<br>Public hospital in Yvelines, France, providing healthcare, education, and research across eight specialized care poles for all ages | Hospitals and Health Care | 🇫🇷 Poissy | 636 |  |
| 9 | [Pôle Emploi](https://www.tamtam.ai/c/pole-emploi) (pole-emploi.fr)<br>Distributor of IKON, a platform helping companies improve IT service performance and business activities through unified real-time monitoring and data management. | Government Administration | 🇫🇷 Plaisir | 511 |  |
| 10 | [CPAM des Yvelines](https://www.tamtam.ai/c/cpam-des-yvelines) (ameli.fr)<br>A private organization serving the CNAM for public service, protecting over 15 million individuals by implementing healthcare policies locally in Yvelines | Government Administration | 🇫🇷 Versailles | 480 | 1981 |
| 11 | [Grand Paris Seine & Oise](https://www.tamtam.ai/c/grand-paris-seine-and-oise) (gpseo.fr)<br>management of a large urban and rural territory focusing on economic sectors, innovation, infrastructure, environment, and public services organization | Government Administration | 🇫🇷 Aubergenville | 429 | 2016 |
| 12 | [Centre Hospitalier de Plaisir](https://www.tamtam.ai/c/centre-hospitalier-de-plaisir) (ch-plaisir.fr)<br>Provides diverse, specialized hospital and outpatient care in South Yvelines, including radiology, MRI, and CT scans, focusing on gerontological, medico-social, and mental health. | Hospitals and Health Care | 🇫🇷 Plaisir | 349 |  |
| 13 | [Centre hospitalier de Rambouillet](https://www.tamtam.ai/c/centre-hospitalier-de-rambouillet) (ch-rambouillet.fr)<br>Provides diverse medical services including imaging, surgery, cardiology, dialysis, emergency care, and laboratory support for local population. | Hospitals and Health Care | 🇫🇷 Rambouillet | 345 | 1731 |
| 14 | [Crous de Versailles](https://www.tamtam.ai/c/crous-de-versailles) (crous-versailles.fr)<br>State operator in charge of all student life aspects, serving 206,000 students in the Versailles academic region through 700 agents | Government Administration | 🇫🇷 Versailles | 344 | 1955 |
| 15 | [Woodford County Public Schools](https://www.tamtam.ai/c/woodford-county-public-schools) (beechwood.kyschools.us)<br>A highly reputable and long-standing educational institution known for its outstanding academic performance in the state | Primary and Secondary Education | 🇫🇷 Versailles | 324 | 1852 |
| 16 | [Cour d'appel de Versailles (78)](https://www.tamtam.ai/c/cour-d-appel-de-versailles-78) (cours-appel.justice.fr)<br>The Court of Appeal of Versailles is a judicial institution handling appeals from lower courts within a jurisdiction covering 4 departments | Courts of Law | 🇫🇷 Versailles | 307 | 1975 |
| 17 | [Lycée Jules Ferry](https://www.tamtam.ai/c/lycee-jules-ferry) (lyc-ferry-versailles.ac-versailles.fr)<br>The company is a high school providing diverse educational pathways in science, technology, literature, languages, humanities, and social sciences to around 2000 students | Education Administration Programs | 🇫🇷 Versailles | 262 | 1907 |
| 18 | [Hôpital de Mantes-la-Jolie](https://www.tamtam.ai/c/hopital-de-mantes-la-jolie) (ghtyvelinesnord.fr)<br>Provides comprehensive, specialized hospital care, day hospital and outpatient surgery, accommodation beds, and various specialized consultations, as part of a public hospital group. | Hospitals and Health Care | 🇫🇷 Mantes-la-Jolie | 253 |  |
| 19 | [Lycée Hoche](https://www.tamtam.ai/c/lycee-hoche) (lyc-hoche-versailles.ac-versailles.fr)<br>College, high school, and preparatory classes provider based in Versailles, France since 1803 Has a strong alumni association | Primary and Secondary Education | 🇫🇷 Versailles | 222 | 1803 |
| 20 | [SIMMT - Structure Intégrée du Maintien en condition opérationnelle des Matériels Terrestres](https://www.tamtam.ai/c/simmt-structure-integree-du-maintien-en-condition-operationnelle-des-materiels) (terre.defense.gouv.fr)<br>Manages operational maintenance for land equipment, ensuring availability for military operations, cost coherence, and logistics for army, directorates, and services. | Armed Forces | 🇫🇷 Versailles | 219 | 2010 |
| 21 | [Caf des Yvelines](https://www.tamtam.ai/c/caf-des-yvelines) (caf.fr)<br>The company is a private organization providing public services in the Yvelines department, handling social benefits, family support, and migrant worker affairs | Government Administration | 🇫🇷 Versailles | 196 |  |
| 22 | [Hôpital de Meulan - Les Mureaux](https://www.tamtam.ai/c/hopital-de-meulan-les-mureaux) (ghtyvelinesnord.fr)<br>Provides hospital care, day care, and consultations in various specialties, part of the Yvelines Nord hospital group. | Hospitals and Health Care | 🇫🇷 Meulan-en-Yvelines | 186 |  |
| 23 | [Sciences Po Saint-Germain-en-Laye](https://www.tamtam.ai/c/sciences-po-saint-germain-en-laye) (sciencespo-saintgermainenlaye.fr)<br>Sciences Po Saint-Germain-en-Laye is a prestigious French institution providing a five-year program in political sciences, law, economics, history, and more, with a strong commitment to social justice and international experiences | Higher Education | 🇫🇷 Saint-Germain-en-Laye | 162 | 2013 |
| 24 | [Ecole nationale supérieure d'architecture de Versailles](https://www.tamtam.ai/c/ecole-nationale-superieure-d-architecture-de-versailles) (archi.fr)<br>Educates future architects through various degrees, encouraging innovation and interdisciplinary collaboration, offering a vibrant learning environment and international partnerships. | Higher Education | 🇫🇷 Versailles | 162 | 1969 |
| 25 | [Ville de Houilles](https://www.tamtam.ai/c/ville-de-houilles) (ville-houilles.fr)<br>The company is located in Houilles, a friendly city near Paris, focusing on urban development with a strong emphasis on quality of life and community engagement | Government Administration | 🇫🇷 Houilles | 154 |  |
| 26 | [Lycée Marie Curie - Versailles](https://www.tamtam.ai/c/lycee-marie-curie-versailles) (lyc-curie-versailles.ac-versailles.fr)<br>A school in Versailles offering various academic programs to 1,700 students, including general and technological courses, specialized baccalaureates, BTS programs, and a preparatory class for top schools | Education | 🇫🇷 Versailles | 142 |  |
| 27 | [Handi Val de Seine](https://www.tamtam.ai/c/handi-val-de-seine) (handivaldeseine.org)<br>A syndicate and management association serving citizens by providing prevention, education, rehabilitation, accommodation, and housing services for people with disabilities | Services for the Elderly and Disabled | 🇫🇷 Verneuil-sur-Seine | 139 | 1969 |
| 28 | [Versailles Grand Parc](https://www.tamtam.ai/c/versailles-grand-parc) (versaillesgrandparc.fr)<br>Versailles Grand Parc supports entrepreneurs and project leaders in urban ecology and innovative mobility, aiming to modernize and enhance their exceptional living environment | Government Administration | 🇫🇷 Versailles | 135 | 2003 |
| 29 | [GRETA des Yvelines](https://www.tamtam.ai/c/greta-des-yvelines) (greta-yvelines.fr)<br>A training organization within the National Education system in the Yvelines region, offering continuing education programs, certifications, and professional development services | Professional Training and Coaching | 🇫🇷 Plaisir | 123 |  |
| 30 | [Ville de Maisons-Laffitte](https://www.tamtam.ai/c/ville-de-maisons-laffitte) (maisonslaffitte.fr)<br>Official online platform providing residents and visitors with information about local administration, services, events, and community resources. | Government Administration | 🇫🇷 Maisons-Laffitte | 112 |  |

## 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 12, 2026.

## More company lists in the Yvelines department

- [The largest companies in the Yvelines department](https://www.tamtam.ai/l/largest-companies-yvelines) (1,469)
- [Multinational companies in the Yvelines department](https://www.tamtam.ai/l/multinational-companies-yvelines) (226)
- [Companies with in-house R&D in the Yvelines department](https://www.tamtam.ai/l/r-and-d-companies-yvelines) (160)
- [IT services companies in the Yvelines department](https://www.tamtam.ai/l/it-services-companies-yvelines) (121)
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- [Distributors and wholesalers in the Yvelines department](https://www.tamtam.ai/l/distributors-and-wholesalers-yvelines) (91)
- [Retail chains in the Yvelines department](https://www.tamtam.ai/l/retail-chains-yvelines) (89)
- [Consulting firms in the Yvelines department](https://www.tamtam.ai/l/consulting-firms-yvelines) (72)
- [Aerospace and defence companies in the Yvelines department](https://www.tamtam.ai/l/aerospace-and-defense-companies-yvelines) (65)
- [Software Development companies in the Yvelines department](https://www.tamtam.ai/l/software-development-companies-yvelines) (56)
- [Business Consulting and Services companies in the Yvelines department](https://www.tamtam.ai/l/business-consulting-and-services-companies-yvelines) (53)
- [Government Administration companies in the Yvelines department](https://www.tamtam.ai/l/government-administration-companies-yvelines) (51)
- [Construction companies in the Yvelines department](https://www.tamtam.ai/l/construction-companies-yvelines) (50)
- [Automotive manufacturers and suppliers in the Yvelines department](https://www.tamtam.ai/l/automotive-companies-yvelines) (49)
- [Motor Vehicle Manufacturing companies in the Yvelines department](https://www.tamtam.ai/l/motor-vehicle-manufacturing-companies-yvelines) (49)
- [SaaS companies in the Yvelines department](https://www.tamtam.ai/l/saas-companies-yvelines) (49)
- [Education providers in the Yvelines department](https://www.tamtam.ai/l/education-companies-yvelines) (46)
- [Industrial Machinery Manufacturing companies in the Yvelines department](https://www.tamtam.ai/l/industrial-machinery-manufacturing-companies-yvelines) (43)
- [Critical infrastructure operators in the Yvelines department](https://www.tamtam.ai/l/critical-infrastructure-operators-yvelines) (41)
- [Family-owned companies in the Yvelines department](https://www.tamtam.ai/l/family-owned-companies-yvelines) (36)
- [Environmental services companies in the Yvelines department](https://www.tamtam.ai/l/environmental-services-companies-yvelines) (35)

## The same list elsewhere in France

- [Public sector organisations in France](https://www.tamtam.ai/l/public-sector-organisations-france) (4,006)
- [Public sector organisations in Île-de-France](https://www.tamtam.ai/l/public-sector-organisations-ile-de-france) (993)
- [Public sector organisations in Auvergne-Rhône-Alpes](https://www.tamtam.ai/l/public-sector-organisations-auvergne-rhone-alpes) (451)
- [Public sector organisations in Grand Est](https://www.tamtam.ai/l/public-sector-organisations-grand-est) (427)
- [Public sector organisations in Provence-Alpes-Côte d'Azur](https://www.tamtam.ai/l/public-sector-organisations-provence-alpes-cote-dazur) (384)
- [Public sector organisations in Occitanie](https://www.tamtam.ai/l/public-sector-organisations-occitanie) (317)
- [Public sector organisations in Nouvelle-Aquitaine](https://www.tamtam.ai/l/public-sector-organisations-nouvelle-aquitaine) (310)
- [Public sector organisations in Hauts-de-France](https://www.tamtam.ai/l/public-sector-organisations-hauts-de-france) (261)
- [Public sector organisations in Pays de la Loire](https://www.tamtam.ai/l/public-sector-organisations-pays-de-la-loire) (185)
- [Public sector organisations in the Bouches-du-Rhône department](https://www.tamtam.ai/l/public-sector-organisations-bouches-du-rhone) (183)
- [Public sector organisations in Normandy](https://www.tamtam.ai/l/public-sector-organisations-normandy) (166)
- [Public sector organisations in Brittany](https://www.tamtam.ai/l/public-sector-organisations-brittany) (165)
- [Public sector organisations in the Nord department](https://www.tamtam.ai/l/public-sector-organisations-nord) (135)
- [Public sector organisations in Bourgogne-Franche-Comté](https://www.tamtam.ai/l/public-sector-organisations-bourgogne-franche-comte) (130)
- [Public sector organisations in Centre-Val de Loire](https://www.tamtam.ai/l/public-sector-organisations-centre-val-de-loire) (121)
- [Public sector organisations in the Rhône department](https://www.tamtam.ai/l/public-sector-organisations-rhone) (120)
- [Public sector organisations in the Haute-Garonne department](https://www.tamtam.ai/l/public-sector-organisations-haute-garonne) (111)
- [Public sector organisations in the Gironde department](https://www.tamtam.ai/l/public-sector-organisations-gironde) (109)
- [Public sector organisations in the Hauts-de-Seine department](https://www.tamtam.ai/l/public-sector-organisations-hauts-de-seine) (96)
- [Public sector organisations in the Seine-Saint-Denis department](https://www.tamtam.ai/l/public-sector-organisations-seine-saint-denis) (91)
- [Public sector organisations in the Isère department](https://www.tamtam.ai/l/public-sector-organisations-isere) (80)
- [Public sector organisations in Paris](https://www.tamtam.ai/l/public-sector-organisations-paris) (460)
- [Public sector organisations in Marseille](https://www.tamtam.ai/l/public-sector-organisations-marseille) (103)
- [Public sector organisations in Toulouse](https://www.tamtam.ai/l/public-sector-organisations-toulouse) (83)

## The same list elsewhere

- [Public sector organisations in the world](https://www.tamtam.ai/l/public-sector-organisations-in-the-world) (18,493)
- [Public sector organisations in Europe](https://www.tamtam.ai/l/public-sector-organisations-in-europe) (8,568)

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Source: https://www.tamtam.ai/l/public-sector-organisations-yvelines