# 34 leading critical infrastructure operators in Thailand
Tamtam tracks 34 critical infrastructure operators headquartered in Thailand. This list ranks all of them by number of employees on LinkedIn, led by QatarEnergy LNG, SCB β Siam Commercial Bank and True Corporation. Their median headcount is 1,312. Half of them were founded in 1983 or later. The most common headquarters are Bangkok (16).
This selection of critical infrastructure operators in Thailand includes large established firms, predominantly in banking, telecommunications, and oil and gas. Notable companies include Siam Commercial Bank, which provides diverse financial products; True Corporation, a telecom company upgrading networks; Thai Airways International, a full-service carrier; and PTT Group, an integrated energy company. The majority of these companies are headquartered in Bangkok, indicating a concentration of essential services in the capital.
Several of these entities were founded in the mid-20th century, such as Bangkok Bank (1944) and KASIKORNBANK (1945), highlighting a long-standing presence in Thailand's economic landscape. However, there are also more recent significant entrants like ttb bank (2021). The data shows a strong presence of financial institutions, with multiple major banks listed.
πΉπ Thailand Β· 34 companies Β· Updated Nov 12, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [QatarEnergy LNG](https://www.tamtam.ai/c/qatarenergy-lng) (qatarenergylng.qa)
A leading LNG producer in Qatar with a capacity of 77 MTPA, delivering clean and reliable energy worldwide while contributing to the local economy and community | Oil and Gas | πΉπ Ras Laffan | 8,678 | 1984 |
| 2 | [SCB β Siam Commercial Bank](https://www.tamtam.ai/c/scb-siam-commercial-bank) (scb.co.th)
Providing diverse financial products and services including retail banking, corporate finance, investment, insurance, and technological innovation for customers. | Banking | πΉπ Bangkok | 6,786 | 1906 |
| 3 | [True Corporation](https://www.tamtam.ai/c/true-corporation) (true.th)
Telecom company upgrading networks and digital services to enhance quality of life, support innovation, and drive Thailand's digital economy. | Telecommunications | πΉπ Bangkok | 6,532 | 1990 |
| 4 | [Thai Airways International](https://www.tamtam.ai/c/thai-airways-international) (thaiairways.com)
A full-service carrier offering passenger and cargo transportation, warehousing, ground handling, catering, and maintenance services worldwide, focusing on safety and quality | Airlines and Aviation | πΉπ Chom Phon | 6,283 | 1960 |
| 5 | [Bangkok Bank](https://www.tamtam.ai/c/bangkok-bank) (bangkokbank.com)
Leading commercial bank in Thailand and Southeast Asia, driving innovation in services and products to meet changing financial landscape | Banking | πΉπ Bangkok | 5,734 | 1944 |
| 6 | [AIS](https://www.tamtam.ai/c/ais-bangkok) (ais.th)
Leading 5G digital service provider in Thailand with the most subscribers, offering mobile, broadband, digital services, eSports, insurance, and more | Telecommunications | πΉπ Bangkok | 5,348 | 1990 |
| 7 | [ttb bank](https://www.tamtam.ai/c/ttb-bank) (ttbbank.com)
Providing comprehensive financial products and services to over 10 million customers, focusing on customer experience and sustainable growth. | Banking | πΉπ Bangkok | 4,792 | 2021 |
| 8 | [KASIKORNBANK](https://www.tamtam.ai/c/kasikornbank) (kasikornbank.com)
A leading Thai bank offering a wide range of financial services with a focus on customer satisfaction, risk management, and sustainable business growth | Banking | πΉπ Bangkok | 4,381 | 1945 |
| 9 | [Krungsri](https://www.tamtam.ai/c/krungsri) (krungsri.com)
Offering diverse financial services including banking, leasing, microfinance, securities, asset management, credit cards, and venture capital investments. | Banking | πΉπ Bangkok | 3,831 | 1945 |
| 10 | [Krungthai Bank](https://www.tamtam.ai/c/krungthai-bank) (krungthai.com)
A financial institution focused on development, providing access to funds, financial literacy, and innovative services to strengthen the economy sustainably | Banking | πΉπ Wattana | 3,023 | 1966 |
| 11 | [Thai Life Insurance Public Company Limited](https://www.tamtam.ai/c/thai-life-insurance-public-company-limited) (thailife.com)
Leading national life insurance provider offering coverage through care and compassion, operating for over eighty years as a top-ranked domestic brand. | Insurance | πΉπ Din Daeng | 2,591 | 1942 |
| 12 | [PTT Group](https://www.tamtam.ai/c/ptt-group) (pttplc.com)
Fully integrated energy company engaged in exploration, production, refining, petrochemical, trading, and regional energy development across ASEAN countries. | Oil and Gas | πΉπ Bangkok | 2,476 | 1978 |
| 13 | [BANPU Public Company Limited](https://www.tamtam.ai/c/banpu-public-company-limited) (banpu.com)
Global energy provider, integrating diverse energy solutions, focusing on decarbonization, gas-power-CCUS, renewables, and next-gen mining for sustainable returns. | Oil and Gas | πΉπ | 2,092 | 1983 |
| 14 | [Bank of Thailand](https://www.tamtam.ai/c/bank-of-thailand) (bot.or.th)
Central bank maintaining economic stability, supervising banking and finance industries, protecting consumers, monitoring illegal activities, collaborating for sustainable economic development. | Banking | πΉπ Bangkok | 1,707 | 1942 |
| 15 | [dtac](https://www.tamtam.ai/c/dtac) (true.th)
A telecommunications and technology company in Thailand merging capabilities to elevate digital networks and services for sustainable living, innovation, and economic growth | Telecommunications | πΉπ Bangkok | 1,640 | 1989 |
| 16 | [Bangkok Airways](https://www.tamtam.ai/c/bangkok-airways) (bangkokair.com)
The company operates regional air services from Thailand to various cities in South East Asia, providing convenient travel options for passengers | Airlines and Aviation | πΉπ Bangkok | 1,395 | 1968 |
| 17 | [Allianz Ayudhya](https://www.tamtam.ai/c/allianz-ayudhya) (allianz.co.th)
Providing comprehensive insurance solutions in Thailand with a strong commitment to customers, employees, and partners since 1951. | Insurance | πΉπ | 1,312 | 1951 |
| 18 | [Muang Thai Life Assurance Public Company Limited](https://www.tamtam.ai/c/muang-thai-life-assurance-public-company-limited) (muangthai.co.th)
A leading life insurance company in Thailand, offering a wide range of products and services to improve customers' health and well-being | Insurance | πΉπ Bangkok | 1,254 | 1951 |
| 19 | [Kiatnakin Phatra Financial Group](https://www.tamtam.ai/c/kiatnakin-phatra-financial-group) (kkpfg.com)
Offering banking, securities, asset management, and capital market services to support customers, employees, shareholders, and national economic growth. | Financial Services | πΉπ Wattana | 1,142 | |
| 20 | [Thai Lion Air](https://www.tamtam.ai/c/thai-lion-air) (lionairthai.com)
An airline offering superior products and services with brand new Boeing aircraft, providing the freedom to fly to destinations | Airlines and Aviation | πΉπ Don Mueang District | 1,109 | 2013 |
| 21 | [Krungthai-AXA Life Insurance PCL.](https://www.tamtam.ai/c/krungthai-axa-life-insurance-pcl) (krungthai-axa.co.th)
Provides life insurance products and financial protection services through a partnership between a major bank and a global asset management group. | Insurance | πΉπ | 988 | 1997 |
| 22 | [Thaioil Group](https://www.tamtam.ai/c/thaioil-group) (thaioilgroup.com)
Large integrated refining and petrochemical operation in Thailand focusing on high performance, sustainable growth, innovation, and corporate social responsibility for long-term success. | Oil and Gas | πΉπ Si Racha | 807 | |
| 23 | [Bangchak Corporation Public Company Limited](https://www.tamtam.ai/c/bangchak-corporation-public-company-limited) (career.bangchak.co.th)
Engaging in energy business, focusing on national energy security with innovation, strengthening business continuity and developing sustainability for organization and Thai society. | Oil and Gas | πΉπ Phra Khanong | 757 | 1984 |
| 24 | [PTG ENERGY](https://www.tamtam.ai/c/ptg-energy) (ptgenergy.co.th)
Operate oil terminals, fuel trade, gas stations, LPG, renewable energy, logistics, equipment management, food and beverage, auto care, electronic money services. | Oil and Gas | πΉπ | 686 | 1988 |
| 25 | [KTC - Krungthai Card](https://www.tamtam.ai/c/ktc-krungthai-card) (ktc.co.th)
Operates credit card business, personal loans, utility payment services, and electronic payment services under various account categories including payment service provider. | Financial Services | πΉπ Bangkok | 555 | 2002 |
| 26 | [B.Grimm](https://www.tamtam.ai/c/b-grimm) (bgrimmgroup.com)
Operates as a multinational conglomerate across energy, healthcare, real estate, and digital technologies, with a long history in infrastructure development. | Utilities | πΉπ Bangkok | 534 | 1878 |
| 27 | [Thai Credit Bank Public Company Limited](https://www.tamtam.ai/c/thai-credit-bank-public-company-limited) (thaicreditbank.com)
Provides comprehensive banking and financial services to customers from its headquarters in Bangkok, supporting economic growth through commercial and retail credit solutions. | Banking | πΉπ | 482 | |
| 28 | [Nok Air](https://www.tamtam.ai/c/nok-air) (nokair.com)
A Thai airline symbolizing friendship and freedom, with a major hub in Don Mueang International Airport and serving domestic passengers in Thailand and Myanmar | Airlines and Aviation | πΉπ Sanam Bin | 472 | 2004 |
| 29 | [Vietjet Thailand](https://www.tamtam.ai/c/vietjet-thailand) (th.vietjetair.com)
Operating extensive low-cost flight network in Thailand and Vietnam, expanding across Asia Pacific, recognized for growth and employee excellence. | Airlines and Aviation | πΉπ Bang Phli | 368 | 2014 |
| 30 | [Thai Smile Airways](https://www.tamtam.ai/c/thai-smile-airways) (thaismileair.com)
A subsidiary airline offering short-haul flights with a 'light premium' experience, affordable prices, and modern services on new Airbus A320-200 Aircraft | Aviation and Aerospace Component Manufacturing | πΉπ Lat Yao | 335 | 2012 |
| 31 | [SCBX](https://www.tamtam.ai/c/scbx) (scbx.com)
Leading financial technology group driving strategic initiatives, investments, partnerships, and innovation to capture growth opportunities and improve quality of life. | Financial Services | πΉπ Bangkok | 334 | |
| 32 | [Gunkul Engineering Public Company Limited](https://www.tamtam.ai/c/gunkul-engineering-public-company-limited) (gunkul.com)
Manufactures electrical equipment, provides turnkey power system construction, and develops utility-scale renewable energy projects across Asia to drive sustainable and innovative energy solutions. | Renewable Energy Power Generation | πΉπ Bangkok | 313 | 1982 |
| 33 | [Symphony Communication Public Company Limited](https://www.tamtam.ai/c/symphony-communication-public-company-limited) (symphony.net.th)
Provides telecommunication services including IPLC, IP-VPN, IIG, and NIX. Delivers premium, reliable solutions, and service innovation to enhance business capabilities. | Telecommunications | πΉπ Chatuchak | 240 | 2005 |
| 34 | [SDEE de la Lozère](https://www.tamtam.ai/c/sdee-de-la-lozere) (sdee-lozere.fr)
The company supports local authorities with rural electrification, public lighting, water, sanitation, roadworks, EV charging, renewable energy, and energy efficiency. | Government Administration | πΉπ Mende | 10 | 1950 |
## 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 Thailand
- [The largest companies in Thailand](https://www.tamtam.ai/l/largest-companies-thailand) (158)
- [Multinational companies in Thailand](https://www.tamtam.ai/l/multinational-companies-thailand) (59)
- [Publicly traded companies in Thailand](https://www.tamtam.ai/l/publicly-traded-companies-thailand) (48)
- [Retail chains in Thailand](https://www.tamtam.ai/l/retail-chains-thailand) (34)
- [Corporate groups and holding companies in Thailand](https://www.tamtam.ai/l/holding-companies-thailand) (32)
- [Manufacturers in Thailand](https://www.tamtam.ai/l/manufacturers-thailand) (26)
## The same list elsewhere
- [Critical infrastructure operators in the world](https://www.tamtam.ai/l/critical-infrastructure-operators-in-the-world) (23,312)
- [Critical infrastructure operators in Asia](https://www.tamtam.ai/l/critical-infrastructure-operators-in-asia) (2,531)
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Source: https://www.tamtam.ai/l/critical-infrastructure-operators-thailand