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The 100 largest critical infrastructure operators in Madrid

Tamtam tracks 140 critical infrastructure operators headquartered in Madrid. This list ranks the 100 largest by number of employees on LinkedIn, led by Telefónica, FCC and Quirónsalud. Their median headcount is 1,475. Half of them were founded in 1969 or later.

🇪🇸 Madrid100 companiesUpdated Oct 24, 2026
#CompanyIndustryHeadquarters EmployeesFounded
1
Telefónicatelefonica.com

Leading global telecommunications company providing advanced infrastructure, innovative digital and data services, focusing on secure, cutting-edge technology and social impact.

Telecommunications 🇪🇸 Madrid 121,569 n/a
2
FCCfcc.es

Global citizen services company with 100+ years of experience in environmental services, water, and infrastructure sectors, operating in 34 countries

Environmental Services 🇪🇸 Madrid 71,000 1900
3
Quirónsaludquironsalud.com

Leader in healthcare in Spain and Europe with over 50,000 professionals and 59 hospitals, focusing on medical research, education, and cutting-edge technology

Wellness and Fitness Services 🇪🇸 Madrid 50,000 1893
4
Grupo Cobragrupocobra.com

Global company with 80 years of experience in industrial engineering and specialized services, present in over 45 countries, focusing on renewable energy and various engineering sectors

Utilities 🇪🇸 Madrid 36,000 1944
5
ACCIONAacciona.com

The company specializes in developing regenerative infrastructure with a focus on sustainability, leading the transition to a low-carbon economy with a positive impact on people and the planet

Utilities 🇪🇸 Madrid 33,828 n/a
6
repsolrepsol.com

A leading player in the oil and gas industry, involved in exploration, production, transformation, development, and marketing of efficient, sustainable energy solutions globally

Oil and Gas 🇪🇸 Madrid 26,030 n/a
7
PreZero Españaprezero.es

The company provides environmentally friendly solutions for waste management and circular economy, serving over 980 municipalities in Spain and Portugal

Environmental Services 🇪🇸 Madrid 14,600 2021
8
Correoscorreos.es

The company is a leader in physical, digital, and parcel communications, offering quality services in the ecommerce value chain, reaching millions of homes and businesses annually

Utilities 🇪🇸 Madrid 13,939 1716
9
Iberiaiberia.com

Spain's number-one airline group and Europe-Latin America market leader. Part of IAG Group and Oneworld Alliance, offers best connections to 700 destinations worldwide.

Airlines and Aviation 🇪🇸 Madrid 11,107 1927
10
Elecnor Groupgrupoelecnor.com

Global corporation specializing in engineering, construction, sustainable projects, infrastructure investments, renewable energy, asset management, and energy transmission across 50 countries.

Construction 🇪🇸 Madrid 10,383 1958
11
Sanitascorporativo.sanitas.es

The company is dedicated to promoting healthier and happier lives through an integrated healthcare model, including insurance, hospitals, rehabilitation centers, and dental clinics

Wellness and Fitness Services 🇪🇸 Madrid 10,198 n/a
12
Endesaendesa.com

Leaders in electricity and natural gas sector. Providing services to millions of clients. Core business is production, transportation, distribution and commercialization of electric power.

Utilities 🇪🇸 Madrid 9,800 1944
13
SACYRsacyr.com

A global group specializing in infrastructure, services, and industrial projects with a focus on sustainability, profitability, and improving daily lives

Civil Engineering 🇪🇸 Madrid 8,854 n/a
14
SEURseur.com

Leading urgent transport provider in Spain, specializing in international deliveries, ecommerce, and temperature-controlled shipments Committed to sustainability and innovation for a better planet

Truck Transportation 🇪🇸 Madrid 8,100 1942
15
Moevemoeveglobal.com

Production of sustainable energies based on green molecules like green hydrogen and 2G biofuels, plus ultrafast electric mobility solutions.

Oil and Gas 🇪🇸 Madrid 7,527 n/a
16
Bankinterbankinter.com

A leading Spanish online banking brand focused on quality customer service and innovation, offering a wide range of financial products and services

Banking 🇪🇸 Madrid 6,427 1965
17
ADIFadif.es

Adif is a public entity that manages and develops railway infrastructure in Spain to promote safe, efficient, and sustainable rail transport

Rail Transportation 🇪🇸 Madrid 6,038 2005
18
CEPSAcepsa.com

A leading international entity specializing in sustainable mobility and energy, with expertise in chemicals and a focus on reducing carbon emissions

Oil and Gas 🇪🇸 Madrid 5,553 n/a
19
Aenaaena.es

A leading airport operator offering efficient, quality services in 46 airports in Spain and 16 internationally, prioritizing customer experience and sustainability

Airlines and Aviation 🇪🇸 Madrid 5,374 1991
20
Ocasoocaso.es

An independent Spanish insurance company founded in 1920, focusing on tradition, commitment, and customer satisfaction through efficient service and long-term employee development

Insurance 🇪🇸 Madrid 4,792 1920
21
Naturgynaturgy.com

A multinational energy company with a 180-year history, focusing on renewables, renewable gas, energy efficiency, and circular economy to create value

Electric Power Generation 🇪🇸 Madrid 4,696 1843
22
Urbaserurbaser.com

A global sustainability-focused company providing environmental management services to over 50 million people in 20 countries through a large network of employees and subsidiaries

Environmental Services 🇪🇸 Madrid 4,472 n/a
23
Santander Corporate & Investment Bankingsantandercib.com

A global banking division specializing in corporate and investment services, offering tailored products to clients in Europe, Latin America, US, and Asia

Financial Services 🇪🇸 Madrid 4,079 n/a
24
HM Hospitaleshmhospitales.com

Private healthcare group with 54 centers offering specialized hospitals, clinics, and integrated care focused on quality, innovation, and patient wellbeing.

Wellness and Fitness Services 🇪🇸 Madrid 3,803 1989
25
Bankiacaixabank.com

Leading Spanish financial institution in retail, business, corporate finance, capital markets, asset management, and private banking across six autonomous communities.

Banking 🇪🇸 Madrid 3,778 2010
26
Vithas

Operates 22 hospitals and 39 medical centers across Spain, providing accredited, high-quality healthcare services to over five million patients annually.

Hospitals and Health Care 🇪🇸 Madrid 3,710 2012
27
santalucía segurossantalucia.es

Providing insurance and related services through multiple companies, focusing on customer care, innovation, and employee well-being across Spain.

Insurance 🇪🇸 Madrid 3,582 1922
28
CAJAMARgrupocooperativocajamar.es

Leading Spanish credit cooperative with over 14 million members, 39 million clients, 1,200+ branches, and 5,000 employees, part of Spain's largest cooperative credit group

Banking 🇪🇸 Madrid 3,457 1946
29
CASERcaser.es

An experienced insurance group offering a wide range of solutions in Home, Auto, Health, and Life insurance, with a strong focus on customer service and professionalism

Insurance 🇪🇸 Madrid 3,263 1942
30
Hospital Universitario La Pazcomunidad.madrid

A public hospital in Madrid that offers specialized healthcare services to patients from Spain and other countries, with a strong reputation in the healthcare industry

Hospitals and Health Care 🇪🇸 Madrid 3,225 1964
31
Hospital Gregorio Marañónhggm.es

A public hospital in Madrid known for highly trained professionals, teaching and research, technological advancements, and national/international specialty care

Medical Practices 🇪🇸 Madrid 3,146 n/a
32
Fundación Hospitalariasfundacionhospitalarias.org

Non-profit institution providing specialized care, assistance, and social reintegration for individuals with mental illness, intellectual disabilities, and other conditions worldwide

Hospitals and Health Care 🇪🇸 Madrid 3,112 1881
33
BBVA en Españabbva.es

A multinational financial group offering services to 53 million clients in over 30 countries, prioritizing a better future for people through education and social entrepreneurship

Banking 🇪🇸 Madrid 2,963 n/a
34
Banco de Españabde.es

National central bank and banking supervisor, managing monetary policy, currency issuance, payment systems, and financial system stability in Spain.

Banking 🇪🇸 Madrid 2,585 1782
35
Banco Popularbancosantander.es

One of the top five banking groups in Spain, focused on retail and commercial banking with a strong customer-centric approach, high credit volume, and international presence

Banking 🇪🇸 Madrid 2,560 1926
36
Santander Españabancosantander.es

Providing innovative banking products and solutions, building lasting customer relationships, supporting personal and business project development with expertise and resources.

Banking 🇪🇸 Madrid 2,386 n/a
37
Aqualiaaqualia.com

Aqualia provides water management services to municipalities and private entities in 18 countries, serving 452 million people with sustainable solutions

Environmental Services 🇪🇸 Madrid 2,316 n/a
38
Mutua Madrileñamutua.es

A leading insurance company with over 169 million clients, ranking first in various insurance categories and expanding internationally Also active in asset management and real estate

Insurance 🇪🇸 Madrid 2,302 1930
39
Alsaalsa.es

With over a century of experience, the company is the leading organization in Spain's road passenger transport sector, offering a wide range of bus services

Ground Passenger Transportation 🇪🇸 Madrid 2,232 1923
40
SegurCaixa Adeslassegurcaixaadeslas.es

A leading Spanish non-life insurance company specializing in health insurance and other sectors Known for its extensive network of medical facilities and high-quality service

Insurance 🇪🇸 Madrid 2,229 n/a
41
FCC Medio Ambientefccma.com

A global leader in environmental services, offering waste collection, recycling, energy recovery, cleaning, maintenance, and industrial waste treatment solutions worldwide

Environmental Services 🇪🇸 Madrid 2,061 1911
42
Allianz Españaallianz.es

Providing life and non-life insurance products, investment solutions, and client services through agents, brokers, and banking networks in Spain.

Insurance 🇪🇸 Madrid 1,952 n/a
43
ACCIONA Energíaacciona-energia.com

Global leader in renewable energy solutions, focused on decarbonizing the economy through sustainable energy practices to combat climate change and promote community well-being

Renewable Energy Power Generation 🇪🇸 Madrid 1,875 n/a
44
ENAIREenaire.es

A company under the Ministry of Transport in Spain managing air navigation services at airports and en-route control centers, part of international aviation alliances

Airlines and Aviation 🇪🇸 Madrid 1,768 1990
45
Metro de Madrid, S.A.metromadrid.es

Management and operation of Madrid's extensive metro network, providing high-quality, innovative, and accessible public transportation services daily.

Urban Transit Services 🇪🇸 Madrid 1,767 1919
46
Exolumexolum.com

A European leader in liquid product logistics, specializing in innovative solutions for biofuels, hydrogen, and circular economy to shape the future

Transportation, Logistics, Supply Chain and Storage 🇪🇸 Madrid 1,650 1927
47
Avanzaavanzagrupo.com

Leading operator in urban and intercity public transport services in Spain Focus on sustainable mobility solutions and expansion through acquisitions and public contracts

Ground Passenger Transportation 🇪🇸 Madrid 1,593 1885
48
Hospital Universitario Ramón y Cajal

A medical practice company located in Madrid, Spain, specializing in providing healthcare services at Hospital Universitario Ramón y Cajal

Medical Practices 🇪🇸 Madrid 1,548 n/a
49
ING España&Portugaling.es

ING Spain & Portugal is a digital bank focusing on simplicity, transparency, innovation, and sustainability to make banking easier for 4 million customers

Banking 🇪🇸 Madrid 1,509 n/a
50
Canal de Isabel IIcanaldeisabelsegunda.es

A public company in Madrid managing the water cycle, ensuring supply and quality, while contributing to environmental protection and using advanced technology

Utilities 🇪🇸 Madrid 1,475 1851
51
EDP Renewablesedpr.com

Global renewable energy company specializing in wind power generation with extensive international presence and significant operating capacity.

Renewable Energy Power Generation 🇪🇸 Madrid 1,449 n/a
52
Openbankopenbank.us

Online bank offering complete, convenient, and fast banking services through phone and internet Accessible anytime via smartphone or tablet, with free debit card and access to Santander ATMs

Banking 🇪🇸 Madrid 1,422 1995
53
UFINETufinet.com

A Latin American carrier of carriers providing high-quality telecom solutions with a carrier-grade network, customer-oriented services, and a wide service portfolio

Telecommunications 🇪🇸 Madrid 1,394 1998
54
ASISAasisa.es

Leading Spanish health insurance company owned by a medical cooperative, reinvesting profits in healthcare services, offering comprehensive coverage to over 1.8 million insured.

Insurance 🇪🇸 Madrid 1,363 1971
55
Eurofins Españaeurofins-megalab.com

Leader in clinical diagnostic testing in Spain with over 35 years of experience Offers over 5,000 different tests, serving 70+ hospitals nationwide

Medical and Diagnostic Laboratories 🇪🇸 Madrid 1,313 1988
56
Sanitas Hospitalessanitas.es

A Madrid-based insurance company providing hospital services, located at CALLE RIBERA DEL LOIRA 52, MADRID, Spain

Hospitals and Health Care 🇪🇸 Madrid 1,309 n/a
57
Ontime Logística Integralontime.es

Comprehensive logistics services including parcel, pallet, full loads, dedicated transport, industrial, pharma, sustainable urban delivery, and multimodal transport across Iberia.

Transportation, Logistics, Supply Chain and Storage 🇪🇸 Madrid 1,306 1991
58
EMT Madridemtmadrid.es

Management of urban bus, public parking, vehicle removal, public bike service BiciMAD, and Madrid cable car operations.

Utilities 🇪🇸 Madrid 1,259 1947
59
Enagásenagas.es

The company is the Technical Manager of the Spanish Gas System, ensuring competition and security, with international presence in Mexico and Chile

Oil and Gas 🇪🇸 Madrid 1,239 1972
60
LogiRAILlogirail.com

LogiRAIL provides global logistics, technology, and handling services for the railway sector in Spain They prioritize agility, efficiency, safety, and customer value

Utilities 🇪🇸 Madrid 1,215 n/a
61
Hospital Universitario San Rafaelhospitalsanrafael.es

The Hospital Universitario San Rafael provides specialized medical and surgical care to patients, focusing on holistic treatment and education in healthcare sciences

Hospitals and Health Care 🇪🇸 Madrid 1,004 1892
62
San Juan de Dios Españasjd.es

Official account of a healthcare organization in Spain dedicated to promoting health and providing care to the vulnerable through a network of facilities and professionals

Health and Human Services 🇪🇸 Madrid 987 1572
63
South Europe Ground Services

Provides ground and passenger assistance services to IAG Group airlines and third-party companies at 38 airports in Spain.

Airlines and Aviation 🇪🇸 Madrid 976 2024
64
BBVA Asset Management en Españabbvaassetmanagement.com

A global asset management unit specializing in investment funds and pension management, known for innovation, excellence, and regional expertise

Investment Management 🇪🇸 Madrid 953 1985
65
CASER RESIDENCIALcaseresidencial.es

A private sociosanitary services provider specializing in elderly care, offering residential centers, day centers, assisted living, home care, and telecare nationwide

Hospitals and Health Care 🇪🇸 Madrid 934 n/a
66
VidaCaixavidacaixa.es

A leading enterprise in the social welfare sector, prioritizing Quality, Trust, and Social Commitment for customers, employees, shareholders, society, and the environment

Insurance 🇪🇸 Madrid 884 1987
67
A&Gayg.es

A&G is a wealth management firm founded in 1987, providing exclusive services to private clients and institutions, with over 126 billion EUR in assets under management

Financial Services 🇪🇸 Madrid 868 1987
68
Wamos Airwamosair.com

Global aviation company operating internationally since 2003

Airlines and Aviation 🇪🇸 Madrid 861 2003
69
Pelayo Mutua de Segurospelayo.com

A fixed premium insurance mutual company in Spain offering a wide range of insurance products with a strong financial position and commitment to social programs

Insurance 🇪🇸 Madrid 838 1933
70
Avatel Telecomavatel.es

A leading Spanish telecommunications provider offering fiber optic, fixed and mobile telephony, and television services Driving technological development and connectivity nationwide

Telecommunications 🇪🇸 Madrid 819 2011
71
EDP Españaedpenergia.es

Global company leading the energy transition with a goal to be 100% green by 2030 Produces over 75% renewable energy and supports a sustainable future

Utilities 🇪🇸 Madrid 805 n/a
72
Liberbankunicajabanco.es

We have merged with Unicaja Banco Stay up to date with news from the entity by following us @UnicajaBanco

Banking 🇪🇸 Madrid 794 n/a
73
Redsys Servicios de Procesamientoredsys.es

Specializing in digital payment solutions with expertise in EMV, contactless, tokenization, wallets, e-commerce, cybersecurity, certification, chargebacks, healthcare, telemedicine, mobility, and transportation services

Financial Services 🇪🇸 Madrid 789 n/a
74
Vodafone Españavodafone.es

The company believes in using technology and connectivity to improve lives and create a more sustainable society, aiming to impact one billion lives positively by 2025

Telecommunications 🇪🇸 Madrid 780 n/a
75
Grupo Hospitalario HLAgrupohla.com

A leading hospital group in Spain providing high-quality healthcare through a network of 18 hospitals and 38 multidisciplinary medical centers

Wellness and Fitness Services 🇪🇸 Madrid 779 1969
76
Babcock Españababcockinternational.com

Leader in emergency air services & aircraft maintenance Specializing in medical emergencies, civil protection, search & rescue, firefighting, and training Operating worldwide with 400 aircraft fleet

Airlines and Aviation 🇪🇸 Madrid 753 1983
77
Renta 4r4.com

A leading independent financial services company in Spain and Latin America, offering wealth management, asset management, brokerage, and corporate finance advisory services

Banking 🇪🇸 Madrid 730 1986
78
Telefónica Españajobs.telefonica.com

A tech-driven organization in Spain focusing on trust, sustainability, and team well-being, connecting talent through innovative work models #ConnectingTalent

Telecommunications 🇪🇸 Madrid 715 1929
79
Solunionsolunion.com

A team of professionals with extensive experience in credit and surety insurance, providing solutions to drive secure business growth and projects

Insurance 🇪🇸 Madrid 713 2013
80
Grenergygrenergy.eu

A project developer and Independent Power Producer specializing in solar and wind energy plants' development, construction, operation, maintenance, and sale

Renewable Energy Power Generation 🇪🇸 Madrid 713 2007
81
Cecabankcecabank.es

Wholesale Spanish bank specializing in securities services, payments, treasury management, and digital solutions, offering tailored financial proposals to help customers achieve business objectives internationally

Banking 🇪🇸 Madrid 685 2012
82
IGNISignis.es

Global renewable energy company focused on clean energy projects, thermal power management, energy management, EPC, and O&M services.

Electric Power Generation 🇪🇸 Madrid 675 2015
83
X-ELIOx-elio.com

Develops renewable energy projects, driving businesses and communities toward a sustainable future, with a global, responsible business model for the planet and inhabitants.

Solar Electric Power Generation 🇪🇸 Madrid 672 2005
84
BME | Bolsas y Mercados Españolesbolsasymercados.es

A company managing financial markets infrastructures in Spain, owned by Grupo SIX, offering global trading services, secure financial information, and payment solutions worldwide

Financial Services 🇪🇸 Madrid 665 n/a
85
ENGIE Españaengie.es

Production of renewable energy, energy management, and industrial solutions supporting clients' transition to carbon neutrality and energy efficiency.

Renewable Energy Semiconductor Manufacturing 🇪🇸 Madrid 659 n/a
86
Cescecesce.es

A group of companies in Europe and Latin America providing comprehensive credit management solutions, export credit insurance, and bonding services for businesses

Insurance 🇪🇸 Madrid 658 1970
87
OW Ocean Windsoceanwinds.com

development, financing, construction, and operation of offshore wind farms delivering reliable, green energy to homes and businesses worldwide

Wind Electric Power Generation 🇪🇸 Madrid 646 2020
88
Iberia Expressiberiaexpress.com

Operating a punctual, efficient low-cost airline with a hybrid business model, offering connecting flights, business class, and sustainability commitments.

Airlines and Aviation 🇪🇸 Madrid 645 2012
89
Clínica Nuestra Señora de la Pazxn--nuestraseoradelapaz-33b.es

A non-profit mental health center in Madrid, Spain, providing patient-centered care and utilizing the latest scientific advancements to serve patients nationwide

Hospitals and Health Care 🇪🇸 Madrid 610 1954
90
Gerencia Asistencial de Atención Primariacomunidad.madrid

A public organization providing healthcare services in the Community of Madrid, focusing on improving health, promoting wellness, and efficient resource management 13,209 professionals involved

Hospitals and Health Care 🇪🇸 Madrid 571 n/a
91
WiZinkwizink.es

Expert digital bank providing consumer financing, savings products, flexible payment platforms, and used vehicle loans for millions of customers across Spain and Portugal.

Banking 🇪🇸 Madrid 567 2016
92
Crédito y Caucióncreditoycaucion.es

Since 1929, this company offers credit insurance to protect businesses from non-payment risks, with a global presence for international trade coverage

Insurance 🇪🇸 Madrid 555 1929
93
DHL Express Españadhl.com

Global leader in logistics and transportation, offering a wide range of services including international delivery, e-commerce solutions, express shipping, and supply chain management

Transportation, Logistics, Supply Chain and Storage 🇪🇸 Madrid 549 1969
94
Plus Ultra Líneas Aéreasplusultra.com

Airline offering high-quality transatlantic flights between Spain and Latin America with modern aircraft, daily frequencies, and competitive pricing.

Airlines and Aviation 🇪🇸 Madrid 527 2011
95
UCI, Unión de Créditos Inmobiliariosuci.com

Providing sustainable loans and mortgages focused on responsible home buying, community rehabilitation, and contributing to urban decarbonization goals.

Banking 🇪🇸 Madrid 515 1989
96
Abertisabertis.com

Management of over 8,000 kilometers of high-capacity toll roads across 15 countries, focusing on safety, technology, and innovation.

Facilities Services 🇪🇸 Madrid 472 n/a
97
GS Inima Environmentinima.com

A global leader in the water sector, specializing in all project phases from design to maintenance, with over 200 completed projects worldwide

Environmental Services 🇪🇸 Madrid 461 1955
98
BANCO COOPERATIVO ESPAÑOLbancocooperativo.es

Provides banking services to rural cooperative banks, emphasizing employee commitment, customer excellence, and strong organizational values.

Banking 🇪🇸 Madrid 441 1990
99
Hospital Universitario Nuestra Señora del Rosariohospitalrosario.es

A surgical medical center in Madrid, offering a wide range of specialties, advanced technology, and 24-hour emergency services for adults and neonates

Wellness and Fitness Services 🇪🇸 Madrid 434 1889
100
Banco Inversisinversis.es

Specialized in high value-added solutions for financial institutions, offering a range of services including trading, settlement, custody, operational procurement, and technology solutions

Investment Banking 🇪🇸 Madrid 422 2000

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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 Oct 24, 2026.

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