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The 26 largest critical infrastructure operators in Seoul

Tamtam tracks 26 critical infrastructure operators headquartered in Seoul. This list ranks all of them by number of employees on LinkedIn, led by SK Innovation, Korean Air and HMM. Their median headcount is 817. Half of them were founded in 1967 or later.

🇰🇷 Seoul26 companiesUpdated Oct 24, 2026
#CompanyIndustryHeadquarters EmployeesFounded
1
SK Innovationskinnovation.com

SK Innovation is a leading energy company focused on sustainable technologies, oil refining, petrochemicals, electric vehicle batteries, and global material solutions

Oil and Gas 🇰🇷 Seoul 3,906 1962
2
Korean Airkoreanair.com

Operating a modern fleet, serving 120 cities globally, providing passenger and cargo air transport with high safety and service standards.

Airlines and Aviation 🇰🇷 Seoul 3,648 1969
3
HMMhmm21.com

Global logistics company providing integrated services through a large fleet, worldwide networks, and expert professionals to lead in shipping industry

Maritime Transportation 🇰🇷 Seoul 3,553 1976
4
Shinhan Bankshinhan.com

A leading South Korean bank offering retail, corporate, and investment banking services to millions of customers domestically and across multiple countries

Financial Services 🇰🇷 Seoul 3,147 1982
5
Hana Bankkebhana.com

A leading bank in South Korea with a focus on ESG management, low-carbon finance, and digital innovation to become a global financial group

Financial Services 🇰🇷 Seoul 1,788 n/a
6
Woori Bankwooribank.com

This company offers a comprehensive range of commercial banking services including deposits, loans, securities, trust accounts, corporate finance, and more

Financial Services 🇰🇷 Seoul 1,441 1899
7
Samsung Medical Centersamsunghospital.com

A leading hospital and cancer center in Korea with cutting-edge technology, patient-centered care, top medical staff, research, education, and future-focused expansion plans

Hospitals and Health Care 🇰🇷 Seoul 1,401 1994
8
KB Kookmin Bank 국민은행kbstar.com

A global financial institution based in Seoul, South Korea, offering a range of personal and corporate banking products and services worldwide

Financial Services 🇰🇷 Seoul 1,209 1963
9
Seoul National University Hospitalsnuh.org

A leading medical center in Korea, pioneering world-class standards in healthcare, medical education, research, and patient care through innovation and globalization

Hospitals and Health Care 🇰🇷 Seoul 1,099 1885
10
GS Caltexgscaltex.com

A leading petroleum company in South Korea, producing high-quality petroleum products and leading economic development through domestic supply and global exports

Oil and Gas 🇰🇷 Seoul 979 1967
11
HANWHA LIFE CO., LTD.company.hanwhalife.com

A leading life insurance company in South Korea, specializing in innovative products and services, digital capabilities, and global expansion in fintech and big data

Financial Services 🇰🇷 Seoul 896 1946
12
Industrial Bank of Koreaibk.co.kr

A state-owned financial institution in South Korea focused on providing services to SMEs and industrial sectors, supporting economic growth

Banking 🇰🇷 Seoul 875 1961
13
Samsung Life Insurancesamsunglife.com

A leading life insurance company in South Korea, committed to protecting lives and assets, promoting family values, and global growth through innovation and community support

Insurance 🇰🇷 Seoul 817 n/a
14
우리은행wooribank.com

Constantly leading innovation and change in the finance industry in South Korea, presenting a new vision for the future

Financial Services 🇰🇷 Seoul 815 1899
15
Samsung Fire & Marine Insurancesamsungfire.com

A leading non-life insurance company, committed to client satisfaction and financial soundness, with a global presence and focus on innovation and competitiveness

Insurance 🇰🇷 Seoul 801 1952
16
Hyundai Capital Services

Global financial arm of Hyundai Motor Group offering auto, corporate, and industrial financing worldwide, focusing on digital transformation and partnerships for business effectiveness and growth

Financial Services 🇰🇷 Seoul 759 1993
17
Bank of Koreabok.or.kr

Established as a central bank in 1950, it aims for price stability through monetary policy, overseeing payment systems, managing foreign reserves, and supervising financial institutions

Government Administration 🇰🇷 Seoul 736 1950
18
Korea Investment & Securities Co., Ltdsecurities.koreainvestment.com

A leading financial company under Korea Investment Holdings, offering diversified services in brokerage, asset management, investment banking, and sales & trading

Investment Banking 🇰🇷 Seoul 709 1974
19
S-OIL Corporations-oil.com

An oil refining company with integrated operations in lubricants and petrochemicals, ensuring stable crude oil imports and superior competitiveness in the market

Oil and Gas 🇰🇷 Seoul 666 1976
20
현대카드·현대커머셜(HyundaiCard·HyundaiCommercial)newsroom.hcs.com

Striving for innovation, providing new value to customers, and transforming into a digital company with services like PLCC, AI, blockchain, and customized solutions

Financial Services 🇰🇷 Seoul 660 2001
21
케이뱅크(Kbank)kbanknow.com

A financial services company that aims to transform our financial lives with practical solutions, fostering growth opportunities in a creative environment

Banking 🇰🇷 Seoul 654 2016
22
Severance Hospitalyuhs.or.kr

Pioneering medical institution founded in 1885, leading in healthcare, education, and research Integral to Korean health and medical history

Hospitals and Health Care 🇰🇷 Seoul 585 1885
23
Jeju Airjejuair.net

A fast-growing Low Cost Carrier in Korea operating Boeing 737-800s with domestic and international destinations, established in 2005

Airlines and Aviation 🇰🇷 Seoul 579 n/a
24
Toss Bank(토스뱅크)toss.im

The team aims to establish a new internet bank in South Korea for financial innovation, offering customer-centric services to underserved communities

Banking 🇰🇷 Seoul 575 n/a
25
KYOBO Life Insurance 교보생명kyobo.co.kr

A company that rewrites the history of life insurance, creating new paths ahead of customer needs, and understanding the changing times

Insurance 🇰🇷 Seoul 567 1958
26
OK금융그룹ok.recruiter.co.kr

A global financial services group in South Korea with around 20 subsidiaries, expanding internationally with a focus on consumer finance and banking

Financial Services 🇰🇷 Seoul 45 1999

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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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