These professional services firms in Japan primarily focus on IT services, business consulting, and staffing. The list includes large corporations like NTT DATA, which provides IT and business consulting, and dentsu, an advertising services giant. Other prominent firms are Nomura, a global financial services group, and PwC Japan, which offers auditing, consulting, and tax services. Many of these companies have substantial employee counts, indicating well-established operations.
A notable pattern among these firms is their strong concentration in Tokyo, with several also headquartered in Chiyoda-ku. The companies span various sectors, from Chiyoda Corporation in oil and gas engineering to JAC Recruitment in staffing, reflecting a diverse professional services landscape.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
NTT DATAnttdata.com
Providing IT and business consulting, digital transformation, managed services, and industry solutions to clients worldwide for long-term success. |
48,385 | |||
| 2 |
dentsudentsu.com
Helping brands predict future opportunities and create growth paths by connecting brand, content, commerce, and experience with creativity. |
19,298 | |||
| 3 |
Nomuranomura.com
A global financial services group connecting markets East & West, serving individuals, institutions, corporates, and governments with creative solutions and thought leadership |
16,671 | |||
| 4 | 7,257 | ||||
| 5 | 4,027 | ||||
| 6 |
Chiyoda Corporationchiyodacorp.com
Global engineering company focused on energy and environment, aiming to be top-tier provider through innovative solutions and sustainable growth strategies |
3,984 | |||
| 7 |
JAC Recruitmentjacgroup.com
Global recruitment consultancy providing specialized services for high-income job positions, with a focus on technology-related roles, interim management solutions, and recruitment process optimization |
3,301 | |||
| 8 |
Toyo Engineering Corporationtoyo-eng.com
Engineering globally to construct plants, focusing on quality, safety, environment, and cost Creating sustainable solutions for energy infrastructure with innovation |
3,002 | |||
| 9 |
Accenture Japanaccenture.com
A global professional services company implementing digital technologies to optimize operations, increase revenue, improve citizen services, and drive visible results for clients worldwide |
2,907 | |||
| 10 |
ABeam Consultingabeam.com
Global consulting firm specializing in business strategy, digital technologies, operational services, and helping clients achieve competitive digital transformation and new business models. |
2,712 | |||
| 11 |
株式会社パソナ (Pasona Inc.)pasona.co.jp
The company focuses on creating social infrastructure to provide job opportunities for individuals to pursue fulfilling careers and lifestyles |
2,442 | |||
| 12 |
Baycurrentbaycurrent.co.jp
BayCurrent Consulting, Inc is a Japanese company with a focus on consulting services, with a diverse team of executives and outside directors |
2,086 | |||
| 13 |
KPMGジャパン／KPMG Japankpmg.com
A group of 7 professional firms in Japan, covering auditing, tax, and advisory services Collaborates with KPMG's global network for comprehensive solutions |
1,753 | |||
| 14 | 
日本アイ・ビー・エム（株）ibm.com
A retail company based in Tokyo, Japan, specializing in providing various products and services to customers in the local area |
1,679 | |||
| 15 |
Future Focus Infotech Private Limitedfocusinfotech.com
Providing strategic digital transformation and IT consulting services with global expertise, customer focus, and innovative, scalable technology solutions. |
1,601 | |||
| 16 |
en world Japan K.K.enworld.com
A leading partner for global talent in Japan and APAC, prioritizing honesty, trust, and customer success in recruitment services |
1,402 | |||
| 17 |
Eurotechnology Japaneurotechnology.com
A leading technology consulting firm in Tokyo, specializing in telecommunications, software, semiconductor, environmental, and financial industries Acquiring, selling, and analyzing Japanese companies |
1,288 | |||
| 18 |
TechnoPro Holdings, Inc.technoproholdings.com
Leading technology-focused staffing and services group with expertise in various technical fields, providing engineering staffing, subcontracting, consulting, and recruiting services to clients globally |
1,286 | |||
| 19 |
Apexapexkk.com
A Tokyo-based executive search firm specializing in recruiting bilingual professionals for mid to senior management positions in Japan |
1,121 | |||
| 20 |
RGF International Recruitmentrgf-hr.com
A global human resource solutions company offering recruitment services for individuals and companies of all sizes across Asia |
982 | |||
| 21 |
Dentsu Digitaldentsudigital.co.jp
Leading provider of digital marketing services in Japan, offering strategy, development, and execution of next-gen marketing and IT platforms, along with DX consulting for business innovation |
930 | |||
| 22 |
EY Japaneyjapan.jp
EY Japan consists of independent member firms collaborating to provide cutting-edge global services in assurance, advisory, tax, and transaction services |
920 | |||
| 23 | 898 | ||||
| 24 |
Oriental Consultants Globalocglobal.jp
A global consulting firm in Japan specializing in infrastructure development and project management for various sectors worldwide |
809 | |||
| 25 |
デロイトトーマツコンサルティング（合同）deloitte.com
A management consulting company based in Tokyo, Japan, specializing in providing strategic advice and solutions to businesses and organizations |
802 | |||
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. | |||||
| 26 |
Kadence Internationalkadence.com
Global market research agency with a personalized approach, specializing in reaching diverse audiences and providing innovative solutions for elevated decision-making |
761 | |||
| 27 |
Nishimura & Asahinishimura.com
A leading international law firm with over 800 professionals offering comprehensive legal services worldwide to promote growth and fairness |
742 | |||
| 28 |
Pasona Group Inc. Global Networkpasona-global.com
Global HR services provider specializing in talent acquisition, outsourcing, international business consulting, and training Strong international presence with 55 offices worldwide |
721 | |||
| 29 |
MC Digital｜エムシーデジタルmcdigital.jp
A technology company backed by Mitsubishi Corporation, specializing in digital transformation consulting, solutions, and AI SaaS to accelerate progress across industries |
649 | |||
| 30 |
Vision Consulting, Inc.visioncon-global.com
Innovative consulting firm from Japan focusing on breaking industry norms, improving business value, and creating new, impactful ventures globally |
646 | |||
| 31 |
GoGlobalgoglobal.com
International HR and Employer of Record service enabling global hiring, management, and payment of talent without local entity setup, ensuring compliance |
616 | |||
| 32 |
Ernst & Young ShinNihon LLC（新日本有限責任監査法人）eyjapan.jp
A leading audit firm in Japan, member of EY, providing audit, assurance, and financial advisory services, prioritizing quality and global trust Visit wwwshinnihonorjp for more information |
543 | |||
| 33 |
BREXA Technology, Inc.technology.brexa.com
Specializing in R&D, the company provides technical engineers for specific projects in machinery, electronics, software, and electrical fields, focusing on automotive, digital appliances, robotics, and medical devices |
539 | |||
| 34 |
Randstad Japanrandstad.co.jp
Specializing in HR services, we match client and candidate needs to exceed expectations and provide staffing, outsourcing, and professional solutions |
531 | |||
| 35 |
株式会社メンバーズ／Members Co.,Ltdmembers.co.jp
Facilitating companies in advancing their decarbonization digital transformation through operational support in digital business Visit website for more information |
527 | |||
| 36 |
ClassNK - Nippon Kaiji Kyokaiclassnk.com
A ship classification society supporting safer, cleaner seas through technical services, certifications, and innovative solutions for digitalization and decarbonization challenges globally |
526 | |||
| 37 |
VisasQ inc.corp.visasq.co.jp
Connecting over 500,000 global experts across 190 countries, offering 1on1 interviews and expert surveys, promoting innovation with strict compliance standards. |
521 | |||
| 38 |
Nippon Steel Engineering Co., Ltd.eng.nipponsteel.com
Designing, constructing, and operating various plants and machinery internationally, specializing in steel, environmental, energy, marine engineering, and building construction solutions |
519 | |||
| 39 |
Mitsubishi Research Institutemri.co.jp
A prestigious think tank and consulting firm founded by Mitsubishi group, providing comprehensive solutions and IT services for sustainable business development |
513 | |||
| 40 |
TechnoPro, Inc.technopro.com
A leading technology staffing services company in Japan with a vast network of engineers providing technology solutions to various industries worldwide |
506 | |||
| 41 |
Anderson Mori & Tomotsuneamt-law.com
Leading full-service law firm in Japan, offering comprehensive legal advice on corporate transactions, M&A, finance, litigation, with bilingual lawyers and global reach |
500 | |||
| 42 |
Borderlink, Inc.alt.borderlink.co.jp
Specializing in preparing ALTs for positions beyond teaching in Japan, providing training and job placement services for foreign workers |
486 | |||
| 43 |
AQaqworks.com
A team of designers, developers, and researchers creating products to empower individuals in learning and accomplishing great things globally Founded in Tokyo, now based in Paris |
475 | |||
| 44 |
Fortience Consulting Inc.fortience.com
Consulting services for manufacturing, distribution, finance, public services, and government sectors with strategic, professional expertise and collaborative results. |
461 | |||
| 45 |
SIGMAXYZ Group（シグマクシス・グループ）sigmaxyz.com
The company focuses on consulting services and investments to create value and solve social issues by utilizing its network strength |
458 | |||
| 46 | 450 | ||||
| 47 |
Oriental Consultantsoriconsul.com
A leading consultancy firm in Japan with 850 engineers and specialists, specializing in road engineering, airports, water systems, infrastructure development, IT, and environmental projects |
430 | |||
| 48 |
PDFMpaejapan.com
An American company founded in Japan in 1955, providing architectural, engineering, and facility maintenance services internationally, with a focus on infrastructure, interiors, and FM support |
430 | |||
| 49 |
株式会社クリーク･アンド･リバー社cri.co.jp
A professional agency specializing in various fields like TV, games, web, art, medical, IT, legal, fashion, and agriculture, providing job opportunities, projects, and copyright monetization |
390 | |||
| 50 |
Nagashima Ohno & Tsunematsunoandt.com
A Tokyo-based organization providing international and commercial legal services, with an extensive overseas network and expertise in corporate transactions and risk management/governance cases |
389 | |||
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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 Nov 12, 2026.
More company lists in Japan
- The largest companies in Japan 932
- Multinational companies in Japan 470
- Companies with in-house R&D in Japan 287
- Manufacturers in Japan 224
- Publicly traded companies in Japan 209
- Corporate groups and holding companies in Japan 181
- Hardware manufacturers in Japan 142
- IT Services and IT Consulting companies in Japan 105
- Education providers in Japan 75
- Companies with a mobile app in Japan 69
- Electronics and semiconductor companies in Japan 68
- IT services companies in Japan 64
- AI companies in Japan 63
- Automotive manufacturers and suppliers in Japan 60
- Critical infrastructure operators in Japan 59
- Higher Education companies in Japan 57
- Research institutes in Japan 55
- Consulting firms in Japan 52
- Chemical companies in Japan 51
- Financial services firms in Japan 50
- Public sector organisations in Japan 48
- Energy companies in Japan 45
- Retail chains in Japan 45
- Appliances, Electrical, and Electronics Manufacturing companies in Japan 40