# 50 leading professional services firms in Ireland

Tamtam tracks 126 professional services firms headquartered in Ireland. This list ranks the 50 largest by number of employees on LinkedIn, led by ICON plc, ICON Strategic Solutions and Cpl. Their median headcount is 734. Half of them were founded in 1996 or later. The most common headquarters are Dublin (31).

These professional services firms in Ireland are mostly large, well-established companies, with a significant number operating globally. ICON plc specializes in accelerating the development of drugs, while Version 1 provides IT services and solutions. Cpl is a global provider of talent solutions, and Linesight offers professional consultancy to the construction industry. Matheson LLP, founded in 1825, is a global legal services provider.

The data shows a strong concentration of headquarters in Dublin, indicating a central hub for professional services in Ireland. While a mix of sectors is present, there is a notable presence of IT services, consulting, and financial services, reflecting a diverse professional landscape.

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

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [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 |  |
| 2 | [ICON Strategic Solutions](https://www.tamtam.ai/c/icon-strategic-solutions) (iconplc.com)<br>Global leader in Functional Service Provision services, offering cost-saving FSP models and clinical expertise to improve business performance Providing industry insights and job opportunities | Pharmaceutical Manufacturing | 🇮🇪 Dublin | 7,496 |  |
| 3 | [Cpl](https://www.tamtam.ai/c/cpl) (cpl.com)<br>Global provider of talent solutions across sectors, with 14,000 employees in 14 countries, specializing in matching the right talent to organizations | Staffing and Recruiting | 🇮🇪 Dublin | 4,748 |  |
| 4 | [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 |
| 5 | [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 |
| 6 | [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 |  |
| 7 | [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 |  |
| 8 | [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 |  |
| 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 | [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 |
| 11 | [Waystone](https://www.tamtam.ai/c/waystone) (waystone.com)<br>Global provider of governance, administration, risk, and compliance services supporting institutional investors and asset managers in managing investment structures. | Financial Services | 🇮🇪 Ballsbridge | 1,610 | 2000 |
| 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 | [Morgan McKinley](https://www.tamtam.ai/c/morgan-mckinley) (morganmckinley.com)<br>Global talent services expert providing recruitment, executive search, and talent acquisition solutions across multiple professional disciplines worldwide. | Staffing and Recruiting | 🇮🇪 Cork | 1,430 |  |
| 14 | [Matheson LLP](https://www.tamtam.ai/c/matheson-llp) (matheson.com)<br>A global legal services provider with expertise in various practice areas, serving internationally focused companies and financial institutions operating in Ireland | Law Practice | 🇮🇪 Dublin | 1,139 | 1825 |
| 15 | [A&L Goodbody LLP](https://www.tamtam.ai/c/a-and-l-goodbody-llp) (algoodbody.com)<br>A leading Irish corporate law firm with over 100 years of experience, serving domestic and international businesses with offices in multiple locations | Law Practice | 🇮🇪 Dublin | 1,054 | 1901 |
| 16 | [CluneTech](https://www.tamtam.ai/c/clunetech) (clunetech.com)<br>Experienced in global payroll, tax returns, promotional management, and cross-border payments Award-winning and innovative financial solutions for multinational corporations | Software Development | 🇮🇪 Kilkenny | 1,021 | 1996 |
| 17 | [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 |  |
| 18 | [OSS](https://www.tamtam.ai/c/oss) (osscompany.ie)<br>This company offers HR expertise and recruitment solutions for the construction industry and events sector, focusing on quality, safety, and operational excellence | Staffing and Recruiting | 🇮🇪 Dublin | 951 | 2009 |
| 19 | [Arthur Cox LLP](https://www.tamtam.ai/c/arthur-cox-llp) (arthurcox.com)<br>Leading law firm in Ireland and beyond, offering comprehensive corporate and business law services to international clients with over 100 years of progressive experience | Law Practice | 🇮🇪 Dublin | 915 | 1920 |
| 20 | [ICDS Group](https://www.tamtam.ai/c/icds-group) (icds.ie)<br>Specializing in staffing solutions for Construction, Civil, Manufacturing, Engineering, Scientific, Medical, Technical, Food, IT, and Finance industries worldwide since 1976 | Staffing and Recruiting | 🇮🇪 Dublin | 858 | 1976 |
| 21 | [Business Services Organisation (BSO)](https://www.tamtam.ai/c/business-services-organisation-bso) (bso.hscni.net)<br>Provider of business support functions and professional services for the Health and Social Care sector in Northern Ireland, offering career opportunities and comprehensive benefits | Hospitals and Health Care | 🇮🇪 Belfast | 844 |  |
| 22 | [Vistatec](https://www.tamtam.ai/c/vistatec) (vistatec.com)<br>A global provider of content solutions, specializing in localization, translation, digital marketing, technical documentation, multimedia, and language automation since 1997 | Translation and Localization | 🇮🇪 Dublin | 796 | 1997 |
| 23 | [My Office](https://www.tamtam.ai/c/my-office) (myoffice.ie)<br>Providing affordable bookkeeping and administration services for businesses, helping them be more efficient and save time and money | Accounting | 🇮🇪 Ennis | 748 |  |
| 24 | [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 |  |
| 25 | [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 |  |
| 26 | [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 |
| 27 | [Mason Hayes & Curran LLP](https://www.tamtam.ai/c/mason-hayes-and-curran-llp) (mhc.ie)<br>Leading law firm in Dublin, with global reach, specializing in energy, technology, finance, construction, and healthcare sectors, offering progressive career opportunities and commitment to social responsibility | Law Practice | 🇮🇪 Dublin | 722 | 1970 |
| 28 | [KTL](https://www.tamtam.ai/c/ktl-naas) (ktl.ie)<br>Industry-leading business in telecoms and power sectors, providing innovative and reliable services to blue chip clients worldwide with a commitment to quality and service excellence | Telecommunications | 🇮🇪 Naas | 720 | 1998 |
| 29 | [Carne Group](https://www.tamtam.ai/c/carne-group) (carnegroup.com)<br>Provides a unified platform for risk, compliance, due diligence, distribution, and governance to simplify asset management operations. | Financial Services | 🇮🇪 Dublin | 712 | 2004 |
| 30 | [TTM Healthcare Group](https://www.tamtam.ai/c/ttm-healthcare-group) (ttmhealthcare.ie)<br>Specialists in healthcare talent management, healthcare process outsourcing & workforce solutions, placing professionals in frontline roles & supporting back-office operations with tailored solutions | Staffing and Recruiting | 🇮🇪 Ennis | 694 | 2002 |
| 31 | [McCann FitzGerald LLP](https://www.tamtam.ai/c/mccann-fitzgerald-llp) (mccannfitzgerald.com)<br>A leading law firm in Ireland with 400 lawyers, offering full services to corporate clients, financial institutions, and international organizations with offices in Dublin, London, New York, and Brussels | Law Practice | 🇮🇪 Dublin | 657 |  |
| 32 | [APC](https://www.tamtam.ai/c/apc-dublin) (approcess.com)<br>This company helps biopharma companies accelerate drug development with breakthrough science, lightning-fast process development, and radical collaboration to deliver for patients faster | Pharmaceutical Manufacturing | 🇮🇪 Dublin | 648 | 2011 |
| 33 | [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 |
| 34 | [Access Healthcare](https://www.tamtam.ai/c/access-healthcare) (accesshealthcare.ie)<br>A healthcare staffing agency focused on understanding and serving nurses and clients, with a high fill rate for nursing shifts | Staffing and Recruiting | 🇮🇪 Dublin | 612 | 2017 |
| 35 | [WILLIAM FRY LLP](https://www.tamtam.ai/c/william-fry-llp) (williamfry.com)<br>A leading Irish law firm with extensive legal and tax expertise, serving domestic and international clients with a focus on achieving results through personalized service and practical solutions | Law Practice | 🇮🇪 Dublin | 576 |  |
| 36 | [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 |
| 37 | [Clarity Locums Ireland - Healthcare Recruitment Specialists](https://www.tamtam.ai/c/clarity-locums-ireland-healthcare-recruitment-specialists) (claritylocums.com)<br>Established in 2012, we provide trusted healthcare staffing services in Ireland and the UK, offering cost-effective solutions for professionals and clients | Staffing and Recruiting | 🇮🇪 Dublin | 546 | 2011 |
| 38 | [Sherry FitzGerald](https://www.tamtam.ai/c/sherry-fitzgerald) (sherryfitz.ie)<br>A leading property advisory firm in Ireland, offering a full range of services nationwide, backed by a team of talented professionals and trusted market insights | Real Estate | 🇮🇪 Sandyford | 534 |  |
| 39 | [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 |
| 40 | [Perigord](https://www.tamtam.ai/c/perigord) (perigord-as.com)<br>Global leader in end-to-end packaging supply chain solutions for the Life Science Industry, specializing in artwork, marcoms, and digital assets | Pharmaceutical Manufacturing | 🇮🇪 Dublin | 501 | 1976 |
| 41 | [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 |
| 42 | [Locumotion Ireland](https://www.tamtam.ai/c/locumotion-ireland) (locumotion.com)<br>This company supports employers and GP doctors in building a sustainable primary healthcare infrastructure in Ireland, offering diverse career opportunities | Staffing and Recruiting | 🇮🇪 Dublin 16 | 489 | 2000 |
| 43 | [RECRUITERS](https://www.tamtam.ai/c/recruiters) (recruiters.ie)<br>A trusted recruitment partner in Ireland, specializing in various industries such as sales, IT, finance, HR, and business operations | Staffing and Recruiting | 🇮🇪 Dublin | 464 | 2006 |
| 44 | [Integrity360](https://www.tamtam.ai/c/integrity360) (integrity360.com)<br>Leading cyber security specialist in Europe, offering a range of services to identify, protect, detect, and respond to cyber risks for mid-market and enterprise organizations | IT Services and IT Consulting | 🇮🇪 Termini | 460 | 2005 |
| 45 | [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 |
| 46 | [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 |
| 47 | [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 |
| 48 | [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 |
| 49 | [Excel Recruitment](https://www.tamtam.ai/c/excel-recruitment) (excelrecruitment.com)<br>Excel Recruitment provides talented workforce solutions across various industries, specializing in Retail, IT, Hospitality, Healthcare, and more, with a track record of industry recognition and awards | Staffing and Recruiting | 🇮🇪 Dublin | 391 | 2001 |
| 50 | [Servisource](https://www.tamtam.ai/c/servisource) (servisource.ie)<br>A fast-growing recruitment agency in Ireland providing temporary, permanent, and healthcare services along with a range of HR solutions and training courses | Staffing and Recruiting | 🇮🇪 Dundalk | 380 | 1999 |

## 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)
- [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)
- [Consulting firms in Ireland](https://www.tamtam.ai/l/consulting-firms-ireland) (65)
- [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

- [Professional services firms in Dublin](https://www.tamtam.ai/l/professional-services-firms-dublin) (75)

## The same list elsewhere

- [Professional services firms in the world](https://www.tamtam.ai/l/professional-services-firms-in-the-world) (24,737)
- [Professional services firms in Europe](https://www.tamtam.ai/l/professional-services-firms-in-europe) (13,698)

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