These Irish consulting firms span a range of specializations, from broad professional services to niche industry expertise. Accenture, with its vast global presence, focuses on digital transformation. ICON plc accelerates drug and device development, while PM Group designs high-tech facilities for sectors like pharma and data centers. Version 1 offers IT services, and KPMG Ireland provides audit, tax, and advisory solutions.
A notable pattern among these companies is their strong concentration in Dublin, which serves as the headquarters for the majority of these large to mid-sized firms. This indicates a centralized hub for professional services and specialized consulting within Ireland.
| # | 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 | 2,343 | ||||
| 9 |
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 | |||
| 10 |
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 | |||
| 11 |
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 | |||
| 12 |
Deloitte Irelanddeloitte.com
Global professional services network delivering solutions and insights to address complex business challenges, with leadership capabilities, experience, and collaboration with clients |
1,594 | |||
| 13 |
First Derivativefirstderivative.com
Provides financial services organizations with data-driven and technology-enabled solutions to navigate digital transformation, improve operations, and manage risk, fostering growth and innovation. |
977 | |||
| 14 |
Forvis Mazars In Irelandforvismazars.com
provides audit, tax, consulting, financial advisory, corporate finance, and outsourcing services to international corporates, SMEs, financial institutions, and public bodies |
739 | |||
| 15 |
DOCSiconplc.com
It is a global leader in Functional Service Provision, offering expertise and models that enhance business performance and reduce costs. |
734 | |||
| 16 | 724 | ||||
| 17 |
Cognizant Life Sciences Manufacturingcognizant.com
End-to-end digital transformation solutions for the Life Sciences industry, specializing in Automation, MES, Data Infrastructure, Lab Processes, and Digital Technologies |
724 | |||
| 18 |
LotusWorkslotusworks.com
LotusWorks is an expert engineering partner specializing in Commissioning, Calibration, Engineering Services, Operations, and Maintenance for leading manufacturers and critical facilities |
634 | |||
| 19 | 569 | ||||
| 20 |
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 | |||
| 21 |
Nearformnearform.com
A team of engineers, designers, and strategists building digital capabilities and solutions for enterprises, modernizing organizations with innovative platforms and systems |
497 | |||
| 22 |
MKOmkoireland.ie
Ireland's largest Planning and Environmental consultancy with 200+ professionals delivering complex projects, adding value through multi-disciplinary expertise, and nationwide experience |
447 | |||
| 23 |
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 | |||
| 24 |
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 | |||
| 25 | 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. | |||||
| 26 |
Shanahan Engineeringshanahanengineering.com
Global energy services company with four decades of experience in power projects worldwide Specializing in construction, commissioning, consultancy services, and manpower supply Trusted by industry leaders |
371 | |||
| 27 | 339 | ||||
| 28 |
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 | |||
| 29 |
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 | |||
| 30 |
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 | |||
| 31 |
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 | |||
| 32 |
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 | |||
| 33 |
Bosonitbosonit.com
IT consultancy specializing in Data & AI transformation, offering services in Data Strategy, Governance, Cloud, Business Intelligence, Artificial Intelligence, DevOps, and Cybersecurity |
302 | |||
| 34 |
daa Internationaldaa-international.com
Unlocking value in airports for investors and state owners by leveraging expertise in airport ownership, investment, and commercial operation |
290 | |||
| 35 |
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 | |||
| 36 |
Auxilionauxilion.com
Award-winning consulting and IT services provider focusing on digital transformation, project management, Microsoft solutions, modern workplace, resourcing, and managed services |
238 | |||
| 37 |
S3 Connected Healths3connectedhealth.com
Specializing in digital health solutions, we design cloud-based therapy management tools and connected devices to empower patients with chronic conditions to take control of their health |
210 | |||
| 38 |
Safety Solutionssafetysolutions.ie
Safety Solutions Group specializes in providing Health and Safety Quality Assurance, Compliance Management, and Training services for various sectors |
202 | |||
| 39 |
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 | |||
| 40 |
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 | |||
| 41 |
emagine - Irelandemagine.org
High-end consulting firm tailoring services to each business, offering expert consultants for scalability, project management, and technology solutions globally |
181 | |||
| 42 |
EDC - Engineering Design Consultantsedcengineers.com
A leading engineering company specializing in environmental, sustainable, electrical and mechanical services for various sectors, focusing on innovative design solutions and client partnerships |
134 | |||
| 43 |
Bluewave Technologybluewavecx.com
Award-winning Salesforce consulting partner offering development, training, implementation, and integration services mainly in Ireland and the UK. |
79 | |||
| 44 |
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 | |||
| 45 |
ProStrategyprostrategy.ie
Provider of business management software solutions & services, specializing in data analytics, ERP, CRM, and IT services to empower clients' success |
78 | |||
| 46 |
Invicaratwinit.com
Invicara provides software for building, infrastructure and cities, creating digital twins to optimize asset management and efficiency for businesses |
74 | |||
| 47 |
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 | |||
| 48 |
DYNEdyneits.com
An IT and services company offering consulting, resourcing, project management, software development, testing, and cloud services to deliver customized solutions efficiently |
40 | |||
| 49 |
Aspera Solutionsasperasolutions.com
A leading ERP partner specializing in Epicor solutions for manufacturing and distribution companies, delivering process improvement, automation, and digital transformation for customers globally |
38 | |||
| 50 |
CBOSIT (Premium Zoho Partner)cbosit.com
Empowering SMBs with Zoho transition and enhancement services, helping businesses optimize processes, drive growth, and foster team collaboration for success |
31 | |||
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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 Ireland
- The largest companies in Ireland 1,769
- Multinational companies in Ireland 564
- SaaS companies in Ireland 203
- Software Development companies in Ireland 176
- Retail chains in Ireland 166
- Financial services firms in Ireland 143
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- Professional services firms in Ireland 126
- Manufacturers in Ireland 125
- Companies with in-house R&D in Ireland 120
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- Hardware manufacturers in Ireland 61
- Government Administration companies in Ireland 57