# Top 30 companies with in-house R&D in the Yvelines department Tamtam tracks 160 companies with in-house R&D headquartered in the Yvelines department. This list ranks the 30 largest by number of employees on LinkedIn, led by Dassault Systèmes, Groupe PSA and Peugeot. Their median headcount is 862. Half of them were founded in 1984 or later. The most common headquarters are Velizy-Villacoublay (13), Versailles (4) and Guyancourt (2). The Yvelines department is home to a significant concentration of large and mid-sized companies engaged in in-house research and development. These firms are primarily in manufacturing sectors such as motor vehicles, aviation and aerospace, and defense, alongside strong representation in civil engineering and software development. Key players include Dassault Systèmes, which pioneers virtual worlds; Groupe PSA (now Stellantis), a major automaker; ArianeGroup, focused on space launch systems; and SOCOTEC, providing services for built assets. A notable pattern is the clustering of headquarters in Vélizy-Villacoublay, indicating a hub for corporate R&D activities within the department. 🇫🇷 Yvelines · 30 companies · Updated Nov 12, 2026 | # | Company | Industry | Headquarters | Employees | Founded | |---|---|---|---|---|---| | 1 | [Dassault Systèmes](https://www.tamtam.ai/c/dassault-systemes) (3ds.com)
Pioneering virtual worlds since 1981, this company offers a platform enabling customers across industries to collaborate, imagine, and create sustainable innovations for real-life impact. | Software Development | 🇫🇷 Velizy-Villacoublay | 27,414 | | | 2 | [Groupe PSA](https://www.tamtam.ai/c/groupe-psa) (groupe-psa.com)
Leading automaker and mobility provider; now known as Stellantis. This entity is one of the world's foremost in vehicle manufacturing and mobility solutions. | Motor Vehicle Manufacturing | 🇫🇷 Velizy-Villacoublay | 16,153 | | | 3 | [Peugeot](https://www.tamtam.ai/c/peugeot) (peugeot.com)
Offers customers exhilarating, quality driving experiences through racy design and uncompromised quality, adding excitement to every journey. | Motor Vehicle Manufacturing | 🇫🇷 Poissy | 9,490 | 1810 | | 4 | [SOCOTEC](https://www.tamtam.ai/c/socotec) (socotec.fr)
Provides services throughout the entire life cycle of built assets for compliance, extended lifespan, improved performance, and people’s safety in construction, infrastructure, and industry. | Environmental Services | 🇫🇷 Guyancourt | 7,326 | 1953 | | 5 | [ArianeGroup](https://www.tamtam.ai/c/arianegroup) (ariane.group)
Designing, developing, manufacturing, and operating space launch systems and strategic missiles for space and defense sectors. | Aviation and Aerospace Component Manufacturing | 🇫🇷 Les Mureaux | 6,651 | | | 6 | [Eiffage Génie Civil](https://www.tamtam.ai/c/eiffage-genie-civil) (eiffagegeniecivil.com)
Specializing in civil engineering, this company designs, builds, maintains, and demolishes ambitious structures in France and internationally with a human perspective | Civil Engineering | 🇫🇷 Velizy-Villacoublay | 3,786 | | | 7 | [Eiffage Route](https://www.tamtam.ai/c/eiffage-route) (eiffageroute.com)
An expert in urban development, Eiffage Route contributes to improving the French road network through design, construction, maintenance, and various other projects | Construction | 🇫🇷 Velizy-Villacoublay | 3,480 | | | 8 | [KNDS France](https://www.tamtam.ai/c/knds-france) (knds.com)
Designing, developing, producing armored vehicles, artillery, guns, turrets, ammunition, and robotic systems, with customer support, for armed forces land combat challenges. | Defense and Space Manufacturing | 🇫🇷 Versailles | 2,894 | | | 9 | [Novares Group](https://www.tamtam.ai/c/novares-group) (novaresteam.com)
Designs, manufactures complex plastic components and systems for the automotive industry, focusing on greener, lighter, and connected cars with intuitive interfaces. | Motor Vehicle Manufacturing | 🇫🇷 Velizy-Villacoublay | 2,833 | 1955 | | 10 | [UVSQ Université de Versailles Saint-Quentin-en-Yvelines](https://www.tamtam.ai/c/uvsq-universite-de-versailles-saint-quentin-en-yvelines) (uvsq.fr)
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 | | 11 | [Safran Landing Systems](https://www.tamtam.ai/c/safran-landing-systems) (safran-group.com)
Specializes in landing gear systems, providing innovative solutions for aircraft safety, performance, and maintenance in both commercial and military sectors. | Aviation and Aerospace Component Manufacturing | 🇫🇷 Velizy-Villacoublay | 1,717 | | | 12 | [LGM](https://www.tamtam.ai/c/lgm-velizy-villacoublay) (lgm.group)
The company offers technological, digital, and software engineering consulting, innovative solution design, and complex electronics production, supporting critical systems and industrial performance. | Engineering Services | 🇫🇷 Velizy-Villacoublay | 1,469 | 1991 | | 13 | [Arquus](https://www.tamtam.ai/c/arquus) (arquus-defense.com)
Leading supplier of ground military vehicles to the French army, combining expertise from Renault Trucks Defense, ACMAT, and Panhard, with 130 years of automotive history. | Defense and Space Manufacturing | 🇫🇷 Versailles | 1,309 | | | 14 | [Jungheinrich France SAS](https://www.tamtam.ai/c/jungheinrich-france-sas) (jungheinrich.fr)
International leader in handling equipment, storage systems, and goods flow management. Offers forklifts, racking, services, and consulting for warehouse logistics needs. | Machinery Manufacturing | 🇫🇷 Velizy-Villacoublay | 909 | | | 15 | [CULLIGAN FRANCE](https://www.tamtam.ai/c/culligan-france) (culligan.fr)
Specialist in water treatment providing softeners, purifiers, and water fountains for homes, businesses, and communities ensuring quality water. | Consumer Services | 🇫🇷 Versailles | 862 | | | 16 | [Emotors](https://www.tamtam.ai/c/emotors) (emotors.com)
Design and manufacturing of electric machines for on-road vehicles, providing solutions for propulsion and power generation in the automotive industry. | Motor Vehicle Manufacturing | 🇫🇷 Carrières-sous-Poissy | 811 | 2018 | | 17 | [Carmat](https://www.tamtam.ai/c/carmat) (carmatsa.com)
Designs, manufactures, and markets the Aeson artificial heart, a physiological and self-regulated device for end-stage biventricular heart failure patients awaiting transplant. | Medical Equipment Manufacturing | 🇫🇷 Velizy-Villacoublay | 760 | 2008 | | 18 | [ENVEA Global](https://www.tamtam.ai/c/envea-global) (envea.global)
Provides advanced certified air quality and emissions monitoring solutions to help industries meet environmental targets and move towards net zero. Prevent harmful environmental pollution. | Industrial Machinery Manufacturing | 🇫🇷 Poissy | 738 | 1978 | | 19 | [Schindler France](https://www.tamtam.ai/c/schindler-france) (schindler.fr)
Design, manufacture, install, maintain, and modernize elevators, escalators, moving walkways, and building mobility management products worldwide. | Transportation Equipment Manufacturing | 🇫🇷 Velizy-Villacoublay | 719 | | | 20 | [Eiffage Métal](https://www.tamtam.ai/c/eiffage-metal) (eiffagemetal.com)
Specializing in turnkey metal construction, Eiffage Métal designs and builds building envelopes, facades, and complex multi-technical projects, with a focus on industrial and wind energy sectors | Construction | 🇫🇷 Velizy-Villacoublay | 607 | | | 21 | [Ateme](https://www.tamtam.ai/c/ateme) (ateme.com)
The company specializes in video delivery solutions such as compression, packaging, cloud DVR, DAI, and CDN for content owners, broadcasters, and service providers | Telecommunications | 🇫🇷 Velizy-Villacoublay | 550 | 1991 | | 22 | [Emitech Group](https://www.tamtam.ai/c/emitech-group) (emitech.fr)
Provides global testing services for automotive, aeronautic, and defense industries, including environmental, mechanical, EMC, and electrical tests on components, systems, and vehicles. | Business Consulting and Services | 🇫🇷 Montigny-le-Bretonneux | 510 | 1989 | | 23 | [4D](https://www.tamtam.ai/c/4d) (us.4d.com)
A full-stack hybrid Low-Code Development platform that enables quick creation and deployment of web, mobile, and desktop applications for businesses worldwide | Software Development | 🇫🇷 Le Pecq | 405 | 1984 | | 24 | [Ineo Defense](https://www.tamtam.ai/c/ineo-defense)
Provides technological solutions and services for defense and security, covering critical communications, electronic warfare, operational system protection, and site surveillance. | Defense and Space Manufacturing | 🇫🇷 Velizy-Villacoublay | 355 | | | 25 | [Egis en France](https://www.tamtam.ai/c/egis-en-france) (egis-group.com)
International consulting, construction engineering, and mobility services company. Designs and operates smart infrastructure and buildings addressing climate challenges for balanced and sustainable territorial development. | Civil Engineering | 🇫🇷 Guyancourt | 349 | | | 26 | [Airbus Defence and Space Cyber](https://www.tamtam.ai/c/airbus-defence-and-space-cyber) (cyber.airbus.com)
Designing, developing, integrating, and deploying reliable cyber security solutions for defense, governmental, and institutional customers, leveraging 30 years of expertise. | IT Services and IT Consulting | 🇫🇷 Élancourt | 308 | | | 27 | [ETANCO Group](https://www.tamtam.ai/c/etanco-group) (etancogroup.com)
Providing a wide range of fixing and fastening solutions for building envelopes, including waterproofing, roofing, cladding, and facades. | Construction | 🇫🇷 Le Pecq | 289 | 1952 | | 28 | [IGIENAIR](https://www.tamtam.ai/c/igienair) (igienair.com)
Specializing in Indoor Air Quality, IGIENAIR offers services for air purification and control, along with monitoring tools for commercial spaces worldwide | Environmental Services | 🇫🇷 Achères | 272 | 2003 | | 29 | [Groupe Airwell](https://www.tamtam.ai/c/groupe-airwell) (airwell.com)
French brand specializing in air conditioning and heating solutions, present in over 80 countries since 1947, a reference in the industry. | Renewable Energy Equipment Manufacturing | 🇫🇷 Montigny-le-Bretonneux | 263 | 1947 | | 30 | [Nissan West Europe – France](https://www.tamtam.ai/c/nissan-west-europe-france) (nissan.fr)
Design and manufacture innovative vehicles including crossovers and electric cars, focusing on accessible technology and customer-centric solutions. | Motor Vehicle Manufacturing | 🇫🇷 Voisins-le-Bretonneux | 252 | 1972 | ## 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) - [IT services companies in the Yvelines department](https://www.tamtam.ai/l/it-services-companies-yvelines) (121) - [IT Services and IT Consulting companies in the Yvelines department](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-yvelines) (118) - [Manufacturers in the Yvelines department](https://www.tamtam.ai/l/manufacturers-yvelines) (109) - [Professional services firms in the Yvelines department](https://www.tamtam.ai/l/professional-services-firms-yvelines) (108) - [Hardware manufacturers in the Yvelines department](https://www.tamtam.ai/l/hardware-companies-yvelines) (106) - [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) - [Public sector organisations in the Yvelines department](https://www.tamtam.ai/l/public-sector-organisations-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 - [Companies with in-house R&D in France](https://www.tamtam.ai/l/r-and-d-companies-france) (8,749) - [Companies with in-house R&D in Île-de-France](https://www.tamtam.ai/l/r-and-d-companies-ile-de-france) (2,695) - [Companies with in-house R&D in Auvergne-Rhône-Alpes](https://www.tamtam.ai/l/r-and-d-companies-auvergne-rhone-alpes) (1,460) - [Companies with in-house R&D in Occitanie](https://www.tamtam.ai/l/r-and-d-companies-occitanie) (680) - [Companies with in-house R&D in Grand Est](https://www.tamtam.ai/l/r-and-d-companies-grand-est) (640) - [Companies with in-house R&D in Provence-Alpes-Côte d'Azur](https://www.tamtam.ai/l/r-and-d-companies-provence-alpes-cote-dazur) (612) - [Companies with in-house R&D in Nouvelle-Aquitaine](https://www.tamtam.ai/l/r-and-d-companies-nouvelle-aquitaine) (566) - [Companies with in-house R&D in the Hauts-de-Seine department](https://www.tamtam.ai/l/r-and-d-companies-hauts-de-seine) (510) - [Companies with in-house R&D in the Rhône department](https://www.tamtam.ai/l/r-and-d-companies-rhone) (509) - [Companies with in-house R&D in Pays de la Loire](https://www.tamtam.ai/l/r-and-d-companies-pays-de-la-loire) (480) - [Companies with in-house R&D in Hauts-de-France](https://www.tamtam.ai/l/r-and-d-companies-hauts-de-france) (410) - [Companies with in-house R&D in Brittany](https://www.tamtam.ai/l/r-and-d-companies-brittany) (366) - [Companies with in-house R&D in the Haute-Garonne department](https://www.tamtam.ai/l/r-and-d-companies-haute-garonne) (323) - [Companies with in-house R&D in the Bouches-du-Rhône department](https://www.tamtam.ai/l/r-and-d-companies-bouches-du-rhone) (320) - [Companies with in-house R&D in the Isère department](https://www.tamtam.ai/l/r-and-d-companies-isere) (304) - [Companies with in-house R&D in Bourgogne-Franche-Comté](https://www.tamtam.ai/l/r-and-d-companies-bourgogne-franche-comte) (261) - [Companies with in-house R&D in the Nord department](https://www.tamtam.ai/l/r-and-d-companies-nord) (237) - [Companies with in-house R&D in Normandy](https://www.tamtam.ai/l/r-and-d-companies-normandy) (227) - [Companies with in-house R&D in the Gironde department](https://www.tamtam.ai/l/r-and-d-companies-gironde) (225) - [Companies with in-house R&D in the Loire-Atlantique department](https://www.tamtam.ai/l/r-and-d-companies-loire-atlantique) (207) - [Companies with in-house R&D in the Essonne department](https://www.tamtam.ai/l/r-and-d-companies-essonne) (198) - [Companies with in-house R&D in Centre-Val de Loire](https://www.tamtam.ai/l/r-and-d-companies-centre-val-de-loire) (195) - [Companies with in-house R&D in Paris](https://www.tamtam.ai/l/r-and-d-companies-paris) (1,249) - [Companies with in-house R&D in Lyon](https://www.tamtam.ai/l/r-and-d-companies-lyon) (192) ## The same list elsewhere - [Companies with in-house R&D in the world](https://www.tamtam.ai/l/r-and-d-companies-in-the-world) (34,346) - [Companies with in-house R&D in Europe](https://www.tamtam.ai/l/r-and-d-companies-in-europe) (20,169) --- Source: https://www.tamtam.ai/l/r-and-d-companies-yvelines