These Dublin-based companies are predominantly large to mid-sized professional services firms, with a strong presence in business consulting, IT services, and accounting. Accenture, with its focus on digital transformation, and ICON plc, specializing in drug and device development, represent the larger end of the spectrum. Other significant firms include PM Group, which designs high-tech facilities, and Version 1, an IT solutions provider.
The data shows a clear concentration of companies offering specialized expertise across various sectors. Many firms, such as KPMG Ireland and Grant Thornton Ireland, provide audit, tax, and advisory services to both domestic and international clients, highlighting Dublin's role as a hub for professional and business support services.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
Accentureaccenture.com
It provides professional services to businesses and governments, focusing on digital transformation, operational optimization, and enhancing citizen services globally. |
687,682 | |||
| 2 |
ICON plciconplc.com
A global company founded in Ireland in 1990, specializing in accelerating the development of drugs and devices to save lives and improve quality of life |
35,001 | |||
| 3 |
PM Grouppmgroup-global.com
Specializes in designing, constructing, and commissioning high-tech facilities for pharma, food, data centers, medical technology, manufacturing, and energy sectors globally. |
4,477 | |||
| 4 |
Version 1version1.com
IT services and solutions provider trusted by global brands, offering independent advice to navigate the evolving IT landscape and drive customer success |
3,944 | |||
| 5 |
KPMG Irelandkpmg.ie
A leading provider of audit, tax, and advisory services for domestic and international clients across all sectors, specializing in driving value and navigating change |
2,978 | |||
| 6 |
Grant Thornton Irelandgrantthornton.ie
Providing innovative financial and business solutions with local expertise and global reach, fostering client relationships and ethical practices. |
2,514 | |||
| 7 |
PwC Irelandpwc.ie
Global network providing assurance, advisory, and tax services with a commitment to quality and building trust in society. |
2,502 | |||
| 8 |
S&W Irelandswgroup.com
Providing expert tax, accountancy, assurance, and advisory services to support Irish and international businesses through growth, risks, and exits. |
2,293 | |||
| 9 |
Covalencovalensolutions.com
A trusted partner providing agile outsourcing solutions to Fortune 500 companies, offering multilingual services in customer experience, operations, and trust & safety |
2,030 | |||
| 10 |
Linesightlinesight.com
Provides professional consultancy, management support, and strategic advice to the global construction industry from concept to completion across diverse sectors worldwide. |
1,931 | |||
| 11 | 569 | ||||
| 12 |
BDO Irelandbdo.ie
BDO Ireland offers personalized services with a human touch, providing practical solutions with intelligence, empathy, and purpose through a global network |
527 | |||
| 13 |
CAE Parc Aviationcae.com
A global aviation services company offering flight crew, aircraft support, MRO services, and job opportunities in various roles within the industry |
428 | |||
| 14 |
ESB Internationalesbinternational.ie
A global engineering consultancy firm serving the utility sector, specializing in delivering large-scale projects to maximize investor returns and minimize project risk |
413 | |||
| 15 | 409 | ||||
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. | |||||
| 16 | 339 | ||||
| 17 |
HPCwearehpc.com
A people development company based in Dublin and Belfast, working with organizations to create high performance cultures through bespoke programs and services |
332 | |||
| 18 |
Nicholas O'Dwyer Ltdnodwyer.com
A global consulting engineering firm offering water, environmental, civil, and structural engineering services for sustainable infrastructure projects in various sectors worldwide |
325 | |||
| 19 |
Ethos Engineeringethoseng.ie
A leading mechanical and electrical consultancy providing services to various sectors, known for sustainability, innovation, and award-winning projects and workplace culture |
318 | |||
| 20 |
GDCL Consulting Engineersgdalyconsulting.com
Provider of civil and structural engineering services, specializing in BIM models, with a track record of successful delivery to local and international clients |
315 | |||
| 21 |
Ireland INCirelandinc.com
A forum facilitating Irish companies' expansion and investment in the US, offering consultancy on growth strategies and hosting events to showcase Irish corporate presence |
314 | |||
| 22 |
RSM Irelandrsmireland.ie
A leading firm in audit, tax, and consulting services with over 200 staff and 3 offices in Ireland Recognized for excellence |
261 | |||
| 23 |
Auxilionauxilion.com
Award-winning consulting and IT services provider focusing on digital transformation, project management, Microsoft solutions, modern workplace, resourcing, and managed services |
238 | |||
| 24 |
Institute of Public Administrationipa.ie
Dedicated to advancing public administration and policy through education, training, consultancy, and research services for public servants in Ireland and abroad |
196 | |||
| 25 |
Crowe Irelandcrowe.com
A leading Chartered Accountancy and Business Advisory practice in Ireland, providing audit, tax, wealth management, and advisory services to a wide range of clients |
196 | |||
| 26 |
Bluewave Technologybluewavecx.com
Award-winning Salesforce consulting partner offering development, training, implementation, and integration services mainly in Ireland and the UK. |
79 | |||
| 27 |
UDG Healthcare (now Inizio)inizio.health
Inizio is a strategic partner in health and life sciences, offering advisory, medical, marketing, communications, and patient engagement services throughout the drug lifecycle |
79 | |||
| 28 |
ProStrategyprostrategy.ie
Provider of business management software solutions & services, specializing in data analytics, ERP, CRM, and IT services to empower clients' success |
78 | |||
| 29 |
Invicaratwinit.com
Invicara provides software for building, infrastructure and cities, creating digital twins to optimize asset management and efficiency for businesses |
74 | |||
| 30 |
Agile Executivesagileexecutives.ie
The Agile Executive helps business owners increase turnover, improve cashflow, and enhance company value by matching them with experienced executives and partners |
54 | |||
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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 11, 2026.
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