Largest companies in Ireland
The 22 companies domiciled in Ireland that trade on a US exchange, ranked by market capitalisation. Domicile comes from each company's own SEC filing, so a company headquartered here but listed only on its home market does not appear.
Combined market cap
$833.898 B
0.8% of all US-listed value
Companies
22
Ranked #9 of 55 countries
Average
$37.904 B
Mean market cap per company
| # | Name | Market cap | Close | Session | Country |
|---|---|---|---|---|---|
| 1 | Seagate TechnologySTX | $184.3B | $805.63 | -9.18% | Ireland |
| 2 | EatonETN | $172.9B | $445.09 | +2.89% | Ireland |
| 3 | AccentureACN | $129.1B | $193.40 | -0.85% | Ireland |
| 4 | Trane TechnologiesTT | $104.8B | $476.39 | +1.20% | Ireland |
| 5 | TE ConnectivityTEL | $63.6B | $219.51 | +0.27% | Ireland |
| 6 | Crh PublicCRH | $56.0B | $83.60 | +1.15% | Ireland |
| 7 | RyanairRYAAY | $29.4B | $55.87 | +2.13% | Ireland |
| 8 | Smurfit WestrockSW | $22.2B | $42.39 | -0.05% | Ireland |
| 9 | Jazz PharmaceuticalsJAZZ | $15.0B | $231.39 | -1.97% | Ireland |
| 10 | James Hardie IndustriesJHX | $14.8B | $25.53 | +1.31% | Ireland |
| 11 | Flutter EntertainmentFLUT | $13.4B | $76.25 | +0.69% | Ireland |
| 12 | IconICLR | $12.4B | $161.69 | -3.94% | Ireland |
| 13 | AlkermesALKS | $6.99B | $41.65 | -2.60% | Ireland |
| 14 | WPPWPP | $5.40B | $25.03 | +1.83% | Ireland |
| 15 | GH ResearchGHRS | $1.48B | $21.52 | -2.93% | Ireland |
| 16 | DoleDOLE | $1.20B | $12.72 | -0.63% | Ireland |
| 17 | Ads-Tec Energy PublicADSE | $740.8M | $9.86 | -1.99% | Ireland |
| 18 | AmarinAMRN | $255.0M | $12.07 | -0.17% | Ireland |
| 19 | BreraSLMT | $43.2M | $3.92 | -0.76% | Ireland |
| 20 | Fusion Fuel GreenHTOO | $15.8M | $2.10 | +0.24% | Ireland |
| 21 | Trinity BiotechTRIB | $5.81M | $7.15 | +23.92% | Ireland |
| 22 | SMX (Security Matters) PublicSMX | $4.13M | $3.79 | -2.82% | Ireland |
All 22 companies. One row per company, with secondary share classes folded into their primary listing. Updated 8 Oct 2026.
Other countries
๐บ๐ธ United States 4,020๐จ๐ฆ Canada 243๐น๐ผ Taiwan 24๐ฌ๐ง United Kingdom 75๐ฐ๐ท South Korea 13๐ณ๐ฑ Netherlands 25๐ฏ๐ต Japan 27๐จ๐ญ Switzerland 25๐จ๐ณ China 249๐ง๐ท Brazil 28๐ฆ๐บ Australia 30๐ฉ๐ช Germany 14๐ซ๐ท France 16๐ช๐ธ Spain 5๐ฎ๐ณ India 9๐ฎ๐ฑ Israel 117๐ฑ๐บ Luxembourg 17๐ฎ๐น Italy 6๐ฉ๐ฐ Denmark 7๐ฒ๐ฝ Mexico 16๐ง๐ฒ Bermuda 36๐ฐ๐พ Cayman Islands 30๐ง๐ช Belgium 7๐ฆ๐ท Argentina 14All countries โ
Figures come from SEC filings and daily market prices. Companies listed only outside the US are not covered: see methodology.