# List of consulting firms in Ireland

Tamtam tracks 65 consulting firms headquartered in Ireland. This list ranks the 50 largest by number of employees on LinkedIn, led by Accenture, ICON plc and PM Group. Their median headcount is 409. Half of them were founded in 1989 or later. The most common headquarters are Dublin (32) and Cork (2).

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.

🇮🇪 Ireland · 50 companies · Updated Nov 12, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Accenture](https://www.tamtam.ai/c/accenture) (accenture.com)<br>It provides professional services to businesses and governments, focusing on digital transformation, operational optimization, and enhancing citizen services globally. | Business Consulting and Services | 🇮🇪 Dublin | 687,682 |  |
| 2 | [ICON plc](https://www.tamtam.ai/c/icon-plc) (iconplc.com)<br>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 | Biotechnology Research | 🇮🇪 Dublin | 35,001 |  |
| 3 | [PM Group](https://www.tamtam.ai/c/pm-group) (pmgroup-global.com)<br>Specializes in designing, constructing, and commissioning high-tech facilities for pharma, food, data centers, medical technology, manufacturing, and energy sectors globally. | Business Consulting and Services | 🇮🇪 Dublin | 4,477 | 1973 |
| 4 | [Version 1](https://www.tamtam.ai/c/version-1) (version1.com)<br>IT services and solutions provider trusted by global brands, offering independent advice to navigate the evolving IT landscape and drive customer success | IT Services and IT Consulting | 🇮🇪 Dublin | 3,944 | 1996 |
| 5 | [KPMG Ireland](https://www.tamtam.ai/c/kpmg-ireland) (kpmg.ie)<br>A leading provider of audit, tax, and advisory services for domestic and international clients across all sectors, specializing in driving value and navigating change | Accounting | 🇮🇪 Dublin | 2,978 |  |
| 6 | [Grant Thornton Ireland](https://www.tamtam.ai/c/grant-thornton-ireland) (grantthornton.ie)<br>Providing innovative financial and business solutions with local expertise and global reach, fostering client relationships and ethical practices. | Professional Services | 🇮🇪 Dublin | 2,514 |  |
| 7 | [PwC Ireland](https://www.tamtam.ai/c/pwc-ireland) (pwc.ie)<br>Global network providing assurance, advisory, and tax services with a commitment to quality and building trust in society. | Professional Services | 🇮🇪 Dublin | 2,502 |  |
| 8 | [daa](https://www.tamtam.ai/c/daa) (daa.ie)<br>Global airport and travel retail group managing airports in Dublin and Cork, operating airport retailing worldwide, and providing aviation consultancy services internationally | Airlines and Aviation | 🇮🇪 Swords | 2,343 | 1937 |
| 9 | [S&W Ireland](https://www.tamtam.ai/c/s-and-w-ireland) (swgroup.com)<br>Providing expert tax, accountancy, assurance, and advisory services to support Irish and international businesses through growth, risks, and exits. | Professional Services | 🇮🇪 Dublin | 2,293 | 1958 |
| 10 | [Covalen](https://www.tamtam.ai/c/covalen-dublin) (covalensolutions.com)<br>A trusted partner providing agile outsourcing solutions to Fortune 500 companies, offering multilingual services in customer experience, operations, and trust & safety | Outsourcing and Offshoring Consulting | 🇮🇪 Dublin | 2,030 |  |
| 11 | [Linesight](https://www.tamtam.ai/c/linesight) (linesight.com)<br>Provides professional consultancy, management support, and strategic advice to the global construction industry from concept to completion across diverse sectors worldwide. | Construction | 🇮🇪 Dublin | 1,931 | 1974 |
| 12 | [Deloitte Ireland](https://www.tamtam.ai/c/deloitte-ireland) (deloitte.com)<br>Global professional services network delivering solutions and insights to address complex business challenges, with leadership capabilities, experience, and collaboration with clients | Management Consulting | 🇮🇪 Dublin 2 | 1,594 |  |
| 13 | [First Derivative](https://www.tamtam.ai/c/first-derivative) (firstderivative.com)<br>Provides financial services organizations with data-driven and technology-enabled solutions to navigate digital transformation, improve operations, and manage risk, fostering growth and innovation. | Capital Markets | 🇮🇪 Newry | 977 |  |
| 14 | [Forvis Mazars In Ireland](https://www.tamtam.ai/c/forvis-mazars-in-ireland) (forvismazars.com)<br>provides audit, tax, consulting, financial advisory, corporate finance, and outsourcing services to international corporates, SMEs, financial institutions, and public bodies | Accounting | 🇮🇪 | 739 |  |
| 15 | [DOCS](https://www.tamtam.ai/c/docs) (iconplc.com)<br>It is a global leader in Functional Service Provision, offering expertise and models that enhance business performance and reduce costs. | Pharmaceutical Manufacturing | 🇮🇪 Leopardstown | 734 |  |
| 16 | [Sepam](https://www.tamtam.ai/c/sepam) (sepam.com)<br>A global engineering and project management company founded in 1976, specializing in major capital projects worldwide with a focus on quality and innovative solutions | Engineering Services | 🇮🇪 Clonmel | 724 | 1976 |
| 17 | [Cognizant Life Sciences Manufacturing](https://www.tamtam.ai/c/cognizant-life-sciences-manufacturing) (cognizant.com)<br>End-to-end digital transformation solutions for the Life Sciences industry, specializing in Automation, MES, Data Infrastructure, Lab Processes, and Digital Technologies | Automation Machinery Manufacturing | 🇮🇪 Ringaskiddy | 724 | 1998 |
| 18 | [LotusWorks](https://www.tamtam.ai/c/lotusworks) (lotusworks.com)<br>LotusWorks is an expert engineering partner specializing in Commissioning, Calibration, Engineering Services, Operations, and Maintenance for leading manufacturers and critical facilities | Engineering Services | 🇮🇪 Sligo | 634 | 1989 |
| 19 | [KSN](https://www.tamtam.ai/c/ksn) (ksn.ie)<br>An Irish-owned consultancy practice offering expert quantity surveying, cost management, and sustainability advice to maximize potential return for clients | Construction | 🇮🇪 Dublin | 569 | 1989 |
| 20 | [BDO Ireland](https://www.tamtam.ai/c/bdo-ireland) (bdo.ie)<br>BDO Ireland offers personalized services with a human touch, providing practical solutions with intelligence, empathy, and purpose through a global network | Accounting | 🇮🇪 Dublin | 527 | 1982 |
| 21 | [Nearform](https://www.tamtam.ai/c/nearform) (nearform.com)<br>A team of engineers, designers, and strategists building digital capabilities and solutions for enterprises, modernizing organizations with innovative platforms and systems | IT Services and IT Consulting | 🇮🇪 Waterford | 497 | 2011 |
| 22 | [MKO](https://www.tamtam.ai/c/mko) (mkoireland.ie)<br>Ireland's largest Planning and Environmental consultancy with 200+ professionals delivering complex projects, adding value through multi-disciplinary expertise, and nationwide experience | Environmental Services | 🇮🇪 Galway | 447 | 2008 |
| 23 | [CAE Parc Aviation](https://www.tamtam.ai/c/cae-parc-aviation) (cae.com)<br>A global aviation services company offering flight crew, aircraft support, MRO services, and job opportunities in various roles within the industry | Airlines and Aviation | 🇮🇪 Dublin | 428 | 1975 |
| 24 | [ESB International](https://www.tamtam.ai/c/esb-international) (esbinternational.ie)<br>A global engineering consultancy firm serving the utility sector, specializing in delivering large-scale projects to maximize investor returns and minimize project risk | Utilities | 🇮🇪 Dublin | 413 | 1975 |
| 25 | [ORS](https://www.tamtam.ai/c/ors) (ors.ie)<br>Leading provider of multidisciplinary design and build services, specializing in civil, structural engineering, project management, health and safety, and energy management for diverse clients. | Construction | 🇮🇪 Dublin | 409 | 1991 |
| 26 | [Shanahan Engineering](https://www.tamtam.ai/c/shanahan-engineering) (shanahanengineering.com)<br>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 | Oil and Gas | 🇮🇪 Dun Laoghaire | 371 | 1979 |
| 27 | [Codec](https://www.tamtam.ai/c/codec) (codec.ie)<br>A leading technology company specializing in Microsoft low-code platform solutions for Public and Healthcare sectors, with a focus on innovation and sustainability | IT Services and IT Consulting | 🇮🇪 Dublin | 339 | 1985 |
| 28 | [HPC](https://www.tamtam.ai/c/hpc-dublin) (wearehpc.com)<br>A people development company based in Dublin and Belfast, working with organizations to create high performance cultures through bespoke programs and services | Professional Training and Coaching | 🇮🇪 Dublin | 332 | 1982 |
| 29 | [Nicholas O'Dwyer Ltd](https://www.tamtam.ai/c/nicholas-o-dwyer-ltd) (nodwyer.com)<br>A global consulting engineering firm offering water, environmental, civil, and structural engineering services for sustainable infrastructure projects in various sectors worldwide | Environmental Services | 🇮🇪 Dublin | 325 | 1932 |
| 30 | [Ethos Engineering](https://www.tamtam.ai/c/ethos-engineering) (ethoseng.ie)<br>A leading mechanical and electrical consultancy providing services to various sectors, known for sustainability, innovation, and award-winning projects and workplace culture | Engineering Services | 🇮🇪 Dublin | 318 | 2005 |
| 31 | [GDCL Consulting Engineers](https://www.tamtam.ai/c/gdcl-consulting-engineers) (gdalyconsulting.com)<br>Provider of civil and structural engineering services, specializing in BIM models, with a track record of successful delivery to local and international clients | Civil Engineering | 🇮🇪 Dublin | 315 | 2011 |
| 32 | [Ireland INC](https://www.tamtam.ai/c/ireland-inc) (irelandinc.com)<br>A forum facilitating Irish companies' expansion and investment in the US, offering consultancy on growth strategies and hosting events to showcase Irish corporate presence | Government Relations Services | 🇮🇪 Dublin | 314 | 2009 |
| 33 | [Bosonit](https://www.tamtam.ai/c/bosonit) (bosonit.com)<br>IT consultancy specializing in Data & AI transformation, offering services in Data Strategy, Governance, Cloud, Business Intelligence, Artificial Intelligence, DevOps, and Cybersecurity | IT Services and IT Consulting | 🇮🇪 Europe | 302 | 2015 |
| 34 | [daa International](https://www.tamtam.ai/c/daa-international) (daa-international.com)<br>Unlocking value in airports for investors and state owners by leveraging expertise in airport ownership, investment, and commercial operation | Airlines and Aviation | 🇮🇪 Swords | 290 | 1937 |
| 35 | [RSM Ireland](https://www.tamtam.ai/c/rsm-ireland) (rsmireland.ie)<br>A leading firm in audit, tax, and consulting services with over 200 staff and 3 offices in Ireland Recognized for excellence | Accounting | 🇮🇪 Dublin | 261 |  |
| 36 | [Auxilion](https://www.tamtam.ai/c/auxilion) (auxilion.com)<br>Award-winning consulting and IT services provider focusing on digital transformation, project management, Microsoft solutions, modern workplace, resourcing, and managed services | IT Services and IT Consulting | 🇮🇪 Dublin | 238 | 2012 |
| 37 | [S3 Connected Health](https://www.tamtam.ai/c/s3-connected-health) (s3connectedhealth.com)<br>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 | Hospitals and Health Care | 🇮🇪 Leopardstown | 210 | 2001 |
| 38 | [Safety Solutions](https://www.tamtam.ai/c/safety-solutions) (safetysolutions.ie)<br>Safety Solutions Group specializes in providing Health and Safety Quality Assurance, Compliance Management, and Training services for various sectors | Public Safety | 🇮🇪 Blanchardstown | 202 | 1996 |
| 39 | [Institute of Public Administration](https://www.tamtam.ai/c/institute-of-public-administration) (ipa.ie)<br>Dedicated to advancing public administration and policy through education, training, consultancy, and research services for public servants in Ireland and abroad | Education | 🇮🇪 Dublin | 196 | 1957 |
| 40 | [Crowe Ireland](https://www.tamtam.ai/c/crowe-ireland) (crowe.com)<br>A leading Chartered Accountancy and Business Advisory practice in Ireland, providing audit, tax, wealth management, and advisory services to a wide range of clients | Accounting | 🇮🇪 Dublin | 196 | 1941 |
| 41 | [emagine - Ireland](https://www.tamtam.ai/c/emagine-ireland) (emagine.org)<br>High-end consulting firm tailoring services to each business, offering expert consultants for scalability, project management, and technology solutions globally | IT Services and IT Consulting | 🇮🇪 Cork | 181 | 1986 |
| 42 | [EDC - Engineering Design Consultants](https://www.tamtam.ai/c/edc-engineering-design-consultants) (edcengineers.com)<br>A leading engineering company specializing in environmental, sustainable, electrical and mechanical services for various sectors, focusing on innovative design solutions and client partnerships | Construction | 🇮🇪 Cork | 134 | 2003 |
| 43 | [Bluewave Technology](https://www.tamtam.ai/c/bluewave-technology) (bluewavecx.com)<br>Award-winning Salesforce consulting partner offering development, training, implementation, and integration services mainly in Ireland and the UK. | IT Services and IT Consulting | 🇮🇪 Dublin | 79 | 2000 |
| 44 | [UDG Healthcare (now Inizio)](https://www.tamtam.ai/c/udg-healthcare-now-inizio) (inizio.health)<br>Inizio is a strategic partner in health and life sciences, offering advisory, medical, marketing, communications, and patient engagement services throughout the drug lifecycle | Pharmaceutical Manufacturing | 🇮🇪 Dublin | 79 |  |
| 45 | [ProStrategy](https://www.tamtam.ai/c/prostrategy) (prostrategy.ie)<br>Provider of business management software solutions & services, specializing in data analytics, ERP, CRM, and IT services to empower clients' success | IT Services and IT Consulting | 🇮🇪 Dublin | 78 | 1985 |
| 46 | [Invicara](https://www.tamtam.ai/c/invicara) (twinit.com)<br>Invicara provides software for building, infrastructure and cities, creating digital twins to optimize asset management and efficiency for businesses | Software Development | 🇮🇪 Dublin | 74 | 2012 |
| 47 | [Agile Executives](https://www.tamtam.ai/c/agile-executives) (agileexecutives.ie)<br>The Agile Executive helps business owners increase turnover, improve cashflow, and enhance company value by matching them with experienced executives and partners | Business Consulting and Services | 🇮🇪 Dublin | 54 | 2019 |
| 48 | [DYNE](https://www.tamtam.ai/c/dyne) (dyneits.com)<br>An IT and services company offering consulting, resourcing, project management, software development, testing, and cloud services to deliver customized solutions efficiently | IT Services and IT Consulting | 🇮🇪 Dublin | 40 | 2012 |
| 49 | [Aspera Solutions](https://www.tamtam.ai/c/aspera-solutions) (asperasolutions.com)<br>A leading ERP partner specializing in Epicor solutions for manufacturing and distribution companies, delivering process improvement, automation, and digital transformation for customers globally | Software Development | 🇮🇪 Dublin | 38 | 1987 |
| 50 | [CBOSIT (Premium Zoho Partner)](https://www.tamtam.ai/c/cbosit-premium-zoho-partner) (cbosit.com)<br>Empowering SMBs with Zoho transition and enhancement services, helping businesses optimize processes, drive growth, and foster team collaboration for success | IT Services and IT Consulting | 🇮🇪 Delgany | 31 | 2018 |

## 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](https://www.tamtam.ai/l/largest-companies-ireland) (1,769)
- [Multinational companies in Ireland](https://www.tamtam.ai/l/multinational-companies-ireland) (564)
- [SaaS companies in Ireland](https://www.tamtam.ai/l/saas-companies-ireland) (203)
- [Software Development companies in Ireland](https://www.tamtam.ai/l/software-development-companies-ireland) (176)
- [Retail chains in Ireland](https://www.tamtam.ai/l/retail-chains-ireland) (166)
- [Financial services firms in Ireland](https://www.tamtam.ai/l/financial-services-firms-ireland) (143)
- [Financial Services companies in Ireland](https://www.tamtam.ai/l/financial-services-companies-ireland) (143)
- [Professional services firms in Ireland](https://www.tamtam.ai/l/professional-services-firms-ireland) (126)
- [Manufacturers in Ireland](https://www.tamtam.ai/l/manufacturers-ireland) (125)
- [Companies with in-house R&D in Ireland](https://www.tamtam.ai/l/r-and-d-companies-ireland) (120)
- [Critical infrastructure operators in Ireland](https://www.tamtam.ai/l/critical-infrastructure-operators-ireland) (118)
- [Companies with a mobile app in Ireland](https://www.tamtam.ai/l/companies-with-mobile-app-ireland) (99)
- [Public sector organisations in Ireland](https://www.tamtam.ai/l/public-sector-organisations-ireland) (88)
- [Retail companies in Ireland](https://www.tamtam.ai/l/retail-companies-ireland) (84)
- [Education providers in Ireland](https://www.tamtam.ai/l/education-companies-ireland) (83)
- [IT Services and IT Consulting companies in Ireland](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-ireland) (83)
- [IT services companies in Ireland](https://www.tamtam.ai/l/it-services-companies-ireland) (77)
- [Construction companies in Ireland](https://www.tamtam.ai/l/construction-companies-ireland) (70)
- [Healthcare providers in Ireland](https://www.tamtam.ai/l/healthcare-providers-ireland) (69)
- [Family-owned companies in Ireland](https://www.tamtam.ai/l/family-owned-companies-ireland) (64)
- [Distributors and wholesalers in Ireland](https://www.tamtam.ai/l/distributors-and-wholesalers-ireland) (63)
- [Subscription businesses in Ireland](https://www.tamtam.ai/l/subscription-businesses-ireland) (62)
- [Hardware manufacturers in Ireland](https://www.tamtam.ai/l/hardware-companies-ireland) (61)
- [Government Administration companies in Ireland](https://www.tamtam.ai/l/government-administration-companies-ireland) (57)

## The same list elsewhere in Ireland

- [Consulting firms in Dublin](https://www.tamtam.ai/l/consulting-firms-dublin) (42)

## The same list elsewhere

- [Consulting firms in the world](https://www.tamtam.ai/l/consulting-firms-in-the-world) (16,009)
- [Consulting firms in Europe](https://www.tamtam.ai/l/consulting-firms-in-europe) (8,900)

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Source: https://www.tamtam.ai/l/consulting-firms-ireland