The Yvelines department hosts a concentration of IT services and IT consulting firms, many of which specialize in cybersecurity. These companies range from established mid-sized firms to younger enterprises. Noteworthy examples include Saphir Group, which provides Industry 4.0 solutions and OT security, and Airbus Defence and Space Cyber, known for its cybersecurity solutions for defense and governmental clients. ERCOM offers cutting-edge cybersecurity and communication network solutions, while Médiane Système specializes in secure real-time operating systems and industrial network solutions.
A significant portion of these companies are headquartered in Velizy-Villacoublay, Versailles, and Élancourt, indicating a geographical cluster within the department. The founding dates show a mix of companies established in the late 1980s and early 2000s, alongside more recent ventures, suggesting a sustained growth in the IT and cybersecurity sectors over several decades.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
Saphir Groupquariq.com
Provides Industry 4.0 solutions, industrial automation, MES/MOM, PLM, data and AI, OT security for manufacturers, from strategy to execution globally. |
380 | |||
| 2 |
Airbus Defence and Space Cybercyber.airbus.com
Designing, developing, integrating, and deploying reliable cyber security solutions for defense, governmental, and institutional customers, leveraging 30 years of expertise. |
308 | |||
| 3 |
act digital EMEA - Alter Solutionsactdigital.com
AI-first multinational technology company providing customized, scalable solutions with local agility and global expertise to create business value. |
284 | |||
| 4 |
Cegedim Outsourcingcegedim-outsourcing.fr
Specializes in IT and BPO services with strong technological partnerships, providing high-level technical expertise and independent consulting. |
230 | |||
| 5 |
TVH Consultingtvhconsulting.fr
An international software company specializing in ERP solutions, systems integration, and industry-specific solutions for various verticals globally |
221 | |||
| 6 |
Médiane Systèmemedianesysteme.com
Specializes in custom secure real-time operating systems, private 5G networks, embedded AI, cybersecurity, and industrial network solutions. |
213 | |||
| 7 |
ERCOMthalesgroup.com
Provides cutting-edge cybersecurity and communication network solutions, including certified secure mobile communication, end-to-end encrypted data sharing, and secure messaging applications for professionals. |
170 | |||
| 8 |
GROUPE ROS DIGITALrosdigital.fr
A comprehensive group offering printing solutions, IT services, cloud storage, telecom solutions, communication products, and LED lighting expertise with dedicated specialists in each field |
136 | |||
| 9 |
NowBrainsnowbrains.com
Specializing in digital transformation and IT expertise for small and medium-sized enterprises, offering services in IT infrastructure, cybersecurity, digital strategy, and more Helping businesses accelerate their potential |
105 | |||
| 10 |
CA-SILCA
IT production services for Groupe Crédit Agricole, including infrastructure management, cloud solutions, big data, SOC operations, and user services |
83 | |||
| 11 |
Tersediatersedia.fr
Provider of IT solutions specializing in global infrastructure distribution, storage, business continuity, and virtualized infrastructure, offering expertise and personalized service |
75 | |||
| 12 |
FraudBusterfraudbuster.mobi
Antifraud services for mobile network operators worldwide with disruptive approach and unique solutions like SIMBuster, and MoMoSe. |
39 | |||
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. | |||||
| 13 |
Vistoryvistory.com
Development of cybersecurity software leveraging blockchain, cloud, and big data technologies to enable digital transformation and industry disruption. |
38 | |||
| 14 |
SI4YOUsi-4you.com
Provides comprehensive IT services including managed IT, cybersecurity, telephony, and custom web application development, guiding businesses through digital transformation with expertise and support. |
36 | |||
| 15 |
MTI France SASfr.mti.com
Provides tailored IT solutions and services in datacentre, security, and managed services with global experience and industry best practices. |
35 | |||
| 16 |
SECUREWAYsecureway.fr
Providing specialized consulting for SAP system compliance with security and regulatory requirements, focusing on authorization management and GRC implementation for businesses. |
24 | |||
| 17 |
CENTHYScenthys.com
Assists and guides leaders and stakeholders in cybersecurity and IT transformation, offering consulting, security and network integration, and managed services. |
23 | |||
| 18 |
ALEZ PC PRESTATAIRE INFORMATIQUEalezpc.com
Provides IT infrastructure maintenance, security solutions, server management, data protection, compliance, and personalized IT training for businesses. |
22 | |||
| 19 |
Equipagesequipages.fr
Equipages specializes in building network and security infrastructure, supplying materials, deployment, maintenance, and providing expert assistance for major accounts with dedication and reliability |
22 | |||
| 20 |
SecInfrasecinfra.fr
Dedicated security infrastructure player, assisting companies in securing their IT infrastructure, offering consulting, managed services, audits, and incident response for robust cybersecurity. |
19 | |||
| 21 |
Insyncominsyncom.fr
Insyncom specializes in IT security and infrastructure, offering managed cloud solutions and technical support for clients undergoing digital transformation |
15 | |||
| 22 |
Intuitemintuitem.com
Company creates cybersecurity software, focusing on governance, risk management, and compliance, using expertise in cloud, data, and AI to help organizations manage cyber challenges. |
14 | |||
| 23 |
Oxiboxoxibox.com
A plug-and-protect cyber-resilience solution that guarantees recovery after any disaster by automating data classification, isolation of backups from production network, and utilizing artificial intelligence |
10 | |||
| 24 |
Bull Nederlandatos.net
A leading provider of secure IT systems, focusing on high-quality solutions for efficient business operations in sectors like retail, manufacturing, government, and finance |
6 | |||
| 25 |
ResoSafegroupe-ros.com
A data security specialist for over 25 years, providing products for protecting data, workstations, email communications, and networks |
3 | |||
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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 Yvelines department
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- Companies with in-house R&D in the Yvelines department 160
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- IT Services and IT Consulting companies in the Yvelines department 118
- Manufacturers in the Yvelines department 109
- Professional services firms in the Yvelines department 108
- Hardware manufacturers in the Yvelines department 106
- Distributors and wholesalers in the Yvelines department 91
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- Public sector organisations in the Yvelines department 65
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- Business Consulting and Services companies in the Yvelines department 53
- Government Administration companies in the Yvelines department 51
- Construction companies in the Yvelines department 50
- Automotive manufacturers and suppliers in the Yvelines department 49
- Motor Vehicle Manufacturing companies in the Yvelines department 49
- SaaS companies in the Yvelines department 49
- Education providers in the Yvelines department 46
- Industrial Machinery Manufacturing companies in the Yvelines department 43
- Critical infrastructure operators in the Yvelines department 41
- Family-owned companies in the Yvelines department 36
The same list elsewhere in France
- Cybersecurity companies in France 958
- Cybersecurity companies in Île-de-France 525
- Cybersecurity companies in the Hauts-de-Seine department 154
- Cybersecurity companies in Auvergne-Rhône-Alpes 91
- Cybersecurity companies in Occitanie 49
- Cybersecurity companies in Provence-Alpes-Côte d'Azur 48
- Cybersecurity companies in the Rhône department 48
- Cybersecurity companies in Hauts-de-France 44
- Cybersecurity companies in Grand Est 40
- Cybersecurity companies in Brittany 37
- Cybersecurity companies in the Bouches-du-Rhône department 36
- Cybersecurity companies in Nouvelle-Aquitaine 35
- Cybersecurity companies in the Nord department 30
- Cybersecurity companies in Pays de la Loire 28
- Cybersecurity companies in the Haute-Garonne department 27
- Cybersecurity companies in the Ille-et-Vilaine department 25
- Cybersecurity companies in Paris 290