| Company | International Turnover | Sector | |
|---|---|---|---|
| 1 | Mercury | €880,000,000 | Mechanical & Electrical Engineering |
| 2 | John Sisk & Son | €770,200,000 | General Building, Civil Engineering |
| 3 | Winthrop | €424,324,711 | General Contractor |
| 4 | Jones Engineering | €372,000,000 | Mechanical, Electrical, Process Engineering |
| 5 | Collen Construction | €278,000,000 | General Building |
| 6 | Dornan | €265,000,000 | Mechanical & Electrical Engineering |
| 7 | STS Group | €170,000,000 | Electrical Engineering |
| 8 | Kirby Group Engineering | €149,252,864 | Mechanical & Electrical Engineering |
| 9 | John Paul Construction | €124,000,000 | General Building, Civil Engineering |
| 10 | King & Moffatt Building Services | €93,000,000 | Mechanical & Electrical Engineering |
| 11 | Wills Bros | €81,000,000 | General Building |
| 12 | Designer Group | €76,874,000 | Mechanical & Electrical, Process Engineering |
| 13 | BAM Ireland | €73,000,000 | General Building, Civil Engineering |
| 14 | Bennett | €70,000,000 | General Building. |
| 15 | Suir Engineering | €67,000,000 | Mechanical & Electrical Engineering |
| 16 | JJ Rhatigan & Company | €61,100,000 | General Building |
| 17 | Ardmac Group Ltd | €60,124,980 | General Building |
| 18 | mac-group | €42,500,000 | General Building, Fit-outs |
| 19 | PJ Hegarty & Sons UC | €35,000,000 | General Building, Civil Engineering |
| 20 | Adston Group Holdings Ltd | €32,054,366 | General Building |
| 21 | Townmore | €28,000,000 | General Building |
| 22 | Lynskey Engineering Ltd | €23,481,000 | Mechanical Engineering |
| 23 | Murphy Ireland | €22,000,000 | General Building, Civil Engineering |
| 24 | Glan Agua/MEIC | €18,524,715 | General Building, Civil Engineering |
| 25 | Flynn | €18,220,070 | General Building |
| 26 | ABM Group | €17,500,000 | General Building, Civil Engineering |
| 27 | Elliott Building & Civil Engineering Ltd | €15,000,000 | General Building, Civil Engineering |
| 28 | Mannings Construction Ltd | €14,900,000 | General Building |
| 29 | DFL | €10,157,974 | General Building |
| 30 | Ganson Building & Civil Engineering Contractors Ltd | €8,621,176 | General Building, Civil Engineering |
