Largest Companies in Ireland (2026)

Accenture is the largest company headquartered in Ireland, with revenue of US$69.7bn, and the only Irish entry in the top 100 of the Fortune 500 Europe, at 54th. The Dublin-based professional services firm provides consulting, technology and managed services, including data and artificial-intelligence work. With 779,000 employees in Fortune's figures it is the largest employer on the Irish list by a wide margin.

CRH is a building-materials group headquartered in Dublin, with revenue of US$37.4bn and profit of US$3.8bn. Fortune reports its figures under US accounting standards. Forbes assigns CRH to the United States in its Global 2000, illustrating how classification of Irish-domiciled groups differs between compilers.

Medtronic is a medical technology company that develops and sells device-based therapies through cardiovascular, neuroscience, medical-surgical and diabetes portfolios. Fortune lists its headquarters as Galway and its revenue as US$36.4bn, up 8.4%, with 95,000 employees.

Smurfit Westrock makes corrugated packaging, containerboard and related paper-based packaging and is headquartered in Dublin. Its revenue rose 47.7% to US$31.2bn, the largest increase on the Irish list, and it climbed 63 places in the European ranking.

Eaton is a power-management company supplying electrical, hydraulic and mechanical power products, organised into electrical and aerospace, vehicle and eMobility segments. Fortune records revenue of US$27.4bn and profit of US$4.1bn, the third-highest profit among Irish companies after Accenture and Medtronic.

Johnson Controls International provides building products and services including fire detection and suppression, security, HVAC equipment and building automation. Fortune lists it in Cork, with revenue of US$27.4bn, almost unchanged on the prior year.

DCC Energy, which Fortune records as having changed its name from DCC on 17 July 2026, is a Dublin-based group focused on the sale, marketing and distribution of energy products. Its revenue fell 6.5% to US$22.7bn, while profit was US$18m.

Trane Technologies makes heating, ventilation and air-conditioning systems, building controls and transport refrigeration, reporting through Americas, EMEA and Asia-Pacific segments. Revenue rose 7.5% to US$21.3bn.

Ryanair Holdings, based in Swords, County Dublin, is the only airline on the Irish list. The low-fare carrier also earns revenue from ancillary services and in-flight sales of food, beverages and merchandise. Its revenue rose 20.4% to US$18.0bn and profit was US$2.5bn.

TE Connectivity designs connectors and sensors for transport, industrial and communications markets. Fortune lists its headquarters as Galway and revenue of US$17.3bn, up 8.9%.

Aon provides risk, reinsurance, health and wealth advisory services through risk-capital and human-capital segments. Headquartered in Dublin, it reported revenue of US$17.2bn and profit of US$3.7bn.

Flutter Entertainment operates online betting and gaming brands including Sky Betting and Gaming, Paddy Power, Betfair and tombola, alongside businesses in Australia, the United States and other markets. Revenue rose 16.6% to US$16.4bn, but it reported a net loss of US$310m.

Adient is an automotive seating supplier that Fortune lists in Dublin. Revenue fell 1.0% to US$14.5bn and it reported a net loss of US$281m, one of two loss-making companies on the Irish list.

Seagate Technology makes hard disk drives and other data-storage products. Fortune notes that it is incorporated in Ireland with executive offices in Singapore. It is a newcomer to the European ranking, with revenue up 34.1% to US$12.2bn.

Kingspan Group, headquartered in Kingscourt, County Cavan, makes insulated panels, insulation boards, roofing and other building-envelope products. Revenue rose 11.5% to US$10.4bn.

Dole is a fresh-produce group that Fortune records as incorporated in Ireland with executive offices in the United States. Revenue was US$9.7bn, up 1.7%.

AerCap Holdings leases, finances and sells commercial aircraft. Fortune notes that it is incorporated in the Netherlands with executive offices in Ireland. With 668 employees it has by far the smallest workforce on the list, but its US$3.75bn profit is among the five highest on the Irish list.

Experian is an information-services company providing credit data, analytics and fraud-prevention tools. Fortune records it as incorporated in Jersey with executive offices in Ireland and with a fiscal year ending in March. Revenue rose 12.3% to US$8.4bn.

ICON is a Dublin-based company that Fortune classifies under health-care pharmacy and other services. Its revenue was US$8.3bn, broadly flat on the prior year, and it fell 25 places in the European ranking.

Kerry Group, which Fortune lists in County Kerry, manufactures taste and nutrition ingredients for the food, beverage and pharmaceutical industries. Revenue fell 14.5% to US$7.6bn, and it dropped 74 places in the European ranking.

ESB is Ireland's state-owned electricity company; Fortune records the government as owning 50% or more. It is the only majority state-owned company on the Irish list, with revenue of US$7.6bn and 9,968 employees.