| 1 | Balfour Beatty Group LIMITED | Ireland | Dublin | 29 Earlsfort Terrace | Dublin | D02 | N/A | 1909 | $4,769,186,930 | 15,774 | N/A | N/A | 905055 |
| 2 | Nishimatsu Construction CO LIMITED | Ireland | Whitehall | Dublin Port Tunnel Office | Dublin | N/A | N/A | 1937 | $3,145,843,200 | 400 | N/A | N/A | 904498 |
| 3 | Greencore Holdings (ireland) LIMITED | Ireland | Dublin | 4th Floor Two the Green | Dublin | K67 E2H3 | N/A | 1993 | $1,760,486,909 | 11,741 | N/A | N/A | 208818 |
| 4 | Penman Holdings LIMITED | Ireland | Dublin | 43 Fitzwilliam Square West | Dublin | D02 K792 | N/A | 1995 | $1,435,421,329 | 1,154 | N/A | N/A | 228287 |
| 5 | Eirgrid Public LIMITED Company | Ireland | Dublin | Legal Department | Dublin | D04 FW28 | eirgrid.***** | 2001 | $1,235,036,740 | 610 | N/A | N/A | 338522 |
| 6 | Winthrop Technologies LIMITED | Ireland | Dublin | Unit 7 Turnpike Business Park | Dublin | D22 CD74 | winthrop.***** | 2000 | $1,168,734,576 | 692 | N/A | N/A | 322865 |
| 7 | Michael Mcnamara & Company Unlimited Company | Ireland | Dublin | Rsm Farrell Grant Sparks Molyneux House | Dublin | D08C8CN | N/A | 1940 | $666,372,377 | 424 | N/A | N/A | 21916 |
| 8 | Dornan Engineering LIMITED | Ireland | Cork | 10 Eastgate Avenue | Cork | T45 PC63 | dornan.***** | 1994 | $639,914,679 | 937 | N/A | N/A | 212757 |
| 9 | Glenveagh Homes LIMITED | Ireland | Naas | Block C Maynooth Business Campus | Kildare | N/A | N/A | 2003 | $622,676,772 | 119 | N/A | N/A | 368093 |
| 10 | Walls Construction LIMITED | Ireland | Dublin | Rosemount House | Dublin | D17 NP20 | walls.***** | 1950 | $621,125,370 | 433 | N/A | N/A | 13243 |
| 11 | John Paul Construction LIMITED | Ireland | Dublin | 3 Arkle Road | Dublin | D18 C9C5 | johnpaulconstruction.***** | 1949 | $617,562,574 | 484 | N/A | N/A | 361432 |
| 12 | Collen Construction LIMITED | Ireland | Dublin | River House | Dublin | D03 P7Y5 | collen.***** | 1984 | $561,481,608 | 345 | N/A | N/A | 100646 |
| 13 | Chadwicks Group LIMITED | Ireland | Dublin | Ashfield | Dublin | D22 W318 | N/A | 1909 | $528,901,008 | 1,888 | N/A | N/A | 3510 |
| 14 | Kirby Group Engineering Unlimited Company | Ireland | Limerick | Raheen Business Park | Limerick | V94 NNC4 | kirbygroup.***** | 1964 | $455,768,983 | 1,158 | N/A | N/A | 41839 |
| 15 | Bam Contractors LIMITED | Ireland | Kill | Kill | Cavan | N/A | N/A | 1993 | $448,149,683 | 701 | N/A | N/A | 199002 |
| 16 | Netgear International LIMITED | Ireland | Cork | 6th Floor, Penrose Two | Cork | T23 YY09 | netgear.***** | 2005 | $438,760,000 | 46 | N/A | N/A | 409506 |
| 17 | Suir Engineering LIMITED | Ireland | Waterford | Unit 9a Cleaboy Business Park | Waterford | X91 PX92 | imtechsuir.***** | 1984 | $423,549,704 | 1,297 | N/A | N/A | 100425 |
| 18 | Enet Communications LIMITED | Ireland | Dublin | Block C Dundrum Business Park | Dublin | D14 E1R9 | culturaltourismireland.***** | 1989 | $367,264,685 | 631 | N/A | N/A | 141524 |
| 19 | Ward & Burke Construction LIMITED | Ireland | Kilcolgan | Stradbally East | Galway | H91 W279 | wardandburke.***** | 2001 | $361,665,877 | 824 | N/A | N/A | 336958 |
| 20 | P. Elliott & Company LIMITED | Ireland | Dublin | Block D, Iveagh Court, Harcourt Road | Dublin | D02 VH94 | N/A | 1942 | $355,550,658 | 340 | N/A | N/A | 55644 |
| 21 | Aramark Ireland Holdings LIMITED | Ireland | Dublin | Newenham House | Dublin | D17 AY61 | aramark.***** | 2000 | $341,171,230 | 4,889 | N/A | N/A | 324452 |
| 22 | Designer Group Engineering Contractors Holdings Designated Activity Company | Ireland | Dublin 11 | 52 Nore Road | Dublin | D11V677 | N/A | 2015 | $336,271,506 | 533 | N/A | N/A | 566987 |
| 23 | Project Management LIMITED | Ireland | Dublin | Killakee House | Dublin | D24 XFW2 | pmgroup-global.***** | 1973 | $330,751,104 | 974 | N/A | N/A | 43789 |
| 24 | Specialist Technical Engineering Services Unlimited Company | Ireland | Waterford | Block 10 Cleaboy Business Park | Waterford | N/A | stsgroup.***** | 2006 | $308,773,678 | 749 | N/A | N/A | 432334 |
| 25 | Bennett (construction) LIMITED | Ireland | Mullingar | Forest Park | West Meath | N91 E1WD | bennettconstruction.***** | 1996 | $286,605,519 | 130 | N/A | N/A | 253920 |
| 26 | Pierse Developments (cork) | Ireland | Dublin 15 | Birmayne House | Dublin | D15A078 | N/A | 1996 | $285,686,496 | 734 | N/A | N/A | 245189 |
| 27 | Topcon Europe B.V. | Ireland | Dublin | 1a Unit 69 Western Parkway B | Dublin | D12 | N/A | 1970 | $264,635,073 | 2 | N/A | N/A | 905022 |
| 28 | J.J. Rhatigan & Company Unlimited Company | Ireland | Galway | Wolfe Tone House | Galway | H91 PW72 | jjrhatigan.***** | 1952 | $263,874,720 | 340 | N/A | N/A | 133463 |
| 29 | Elliott Holdings LIMITED | Ireland | Cavan | C/o Advance Asset Management Latt | Cavan | N/A | N/A | 1984 | $256,683,284 | 263 | N/A | N/A | 103584 |
| 30 | Ardmac Group LIMITED | Ireland | Swords | Swords Business Campus | Dublin | K67 Y2P7 | ardmac.***** | 1977 | $250,694,810 | 715 | N/A | N/A | 58640 |
| 31 | Gmc Utilities Group LIMITED | Ireland | Dublin | Gmc House, Millennium Business Park | Dublin | D11ER02 | donedeal.***** | 1981 | $225,971,414 | 523 | N/A | N/A | 374023 |
| 32 | Structuretone LIMITED | Ireland | Dublin | 1st Floor | Dublin | D02 HC65 | structuretone.***** | 2000 | $215,296,996 | 124 | N/A | N/A | 324621 |
| 33 | Wills Bros LIMITED | Ireland | Ballina | Ballylahan Bridge | Mayo | F26 NP92 | willsbros.***** | 1983 | $208,995,854 | 418 | N/A | N/A | 75629 |
| 34 | Bowen Construction LIMITED | Ireland | Cork | C/o Grant Thornton 24/26 City Quay | Cork | D02NY19 | N/A | 1968 | $208,544,684 | 202 | N/A | N/A | 26240 |
| 35 | Conack Construction Unlimited Company | Ireland | Limerick | Unit 1c Eastway Business Park | Limerick | V94 TD90 | conack.***** | 2008 | $205,554,408 | 200 | N/A | N/A | 464473 |
| 36 | Carterton Investments LIMITED | Ireland | Dublin 18 | Mercury House | Dublin | D18XH79 | N/A | 1972 | $195,128,359 | 1,876 | N/A | N/A | 38050 |
| 37 | Tsl Projects LIMITED | Ireland | Kildare | Maynooth Business Campus Unit F11 | Kildare | W23 HR64 | N/A | 2011 | $177,986,248 | 38 | N/A | N/A | 501517 |
| 38 | Equisisk Community Care Partnership LIMITED | Ireland | Dublin | Pembroke Hall | Dublin | N/A | N/A | 2022 | $175,140,920 | 3 | N/A | N/A | 721603 |
| 39 | Elliott Building And Civil Engineering LIMITED | Ireland | Cavan | Station House | Cavan | H12 DA52 | elliottgroup.***** | 1927 | $165,958,825 | 127 | N/A | N/A | 492169 |
| 40 | Mcinerney Homes LIMITED | Ireland | Waterford | Mcinerney House Block 10 | Waterford | N/A | mcinerneyhomes.***** | 1909 | $165,824,923 | 256 | N/A | N/A | 24066 |
| 41 | Radley Engineering LIMITED | Ireland | Waterford | Killadangan Dungarvan | Waterford | X35 X859 | radleyeng.***** | 1972 | $165,092,907 | 573 | N/A | N/A | 38811 |
| 42 | Cooper Industries Trading Unlimited Company | Ireland | Dublin | Eaton House 30 Pembroke Road | Dublin | D04Y0C2 | N/A | 1988 | $164,477,000 | 30 | N/A | N/A | 128031 |
| 43 | Flynn Management & Contractors LIMITED | Ireland | Dublin 11 | Flynn House | Dublin | D11 KN66 | N/A | 2004 | $156,701,968 | 189 | N/A | N/A | 385495 |
| 44 | Kingspan LIMITED | Ireland | Kingscourt | Carrickmacross Road | Cavan | A82 E897 | kingspan.***** | 1973 | $150,266,929 | 192 | N/A | N/A | 40188 |
| 45 | Tli Group LIMITED | Ireland | Tralee | Beenreigh | Kerry | V92 YE97 | tli.***** | 2000 | $145,915,352 | 777 | N/A | N/A | 318301 |
| 46 | Bam Property LIMITED | Ireland | Kildare | Kill | Kildare | N/A | bamcontractors.***** | 1983 | $139,350,267 | 1,101 | N/A | N/A | 94457 |
| 47 | Jons Civil Engineerng Company LIMITED | Ireland | Drogheda | Drogheda Road | Louth | A92 K654 | jonscivil.***** | 1983 | $138,342,943 | 215 | N/A | N/A | 94338 |
| 48 | J. & M. Mccabe Properties LIMITED | Ireland | Dublin | St. John'S House High Street | Dublin | D24N9CA | N/A | 1983 | $137,137,780 | 105 | N/A | N/A | 98238 |
| 49 | Vision Contracting LIMITED | Ireland | Cork | Melbourne House | Cork | T12 YH31 | visioncontracting.***** | 2011 | $133,641,229 | 107 | N/A | N/A | 495829 |
| 50 | Monami Construction LIMITED | Ireland | Galway | Unit 12 Briarhill Business Park | Galway | H91 HH76 | monami.***** | 2011 | $131,277,400 | 105 | N/A | N/A | 494628 |
| 51 | Dres Developments LIMITED | Ireland | Dublin | Third Floor | Dublin | D04 WN59 | N/A | 2017 | $129,388,230 | 78 | N/A | N/A | 599502 |
| 52 | Duggan Brothers (contractors) LIMITED | Ireland | Templemore | Richmond | North Tipperary | E41 R822 | dugganbrothers.***** | 1926 | $127,270,107 | 112 | N/A | N/A | 22567 |
| 53 | Abbeygale Unlimited Company | Ireland | Roscrea | Abbey Mills | North Tipperary | E53 HE94 | N/A | 1990 | $122,253,601 | 97 | N/A | N/A | 156221 |
| 54 | Nordex Energy Ireland LIMITED | Ireland | Limerick | Oola Enterprise Centre | Limerick | E34 F859 | N/A | 2009 | $121,117,352 | 104 | N/A | N/A | 478724 |
| 55 | Jons Civil Engineering John Cradock LIMITED | Ireland | Duleek | Carrstown | Meath | N/A | jonscivil.***** | 2020 | $120,252,381 | 249 | N/A | N/A | 663382 |
| 56 | Freefoam Building Products LIMITED | Ireland | Cork | Central Commercial Park | Cork | T12 R682 | freefoam.***** | 1987 | $114,722,180 | 323 | N/A | N/A | 126587 |
| 57 | Breedon Surfacing Solutions Ireland LIMITED | Ireland | Dublin | Stadium Business Park | Dublin | D11 K2TP | breedongroup.***** | 1986 | $114,368,915 | 46 | N/A | N/A | 115014 |
| 58 | Dayton Investments LIMITED | Ireland | Dublin | 10 Herbert Street | Dublin | D02 EF99 | N/A | 1992 | $112,601,307 | 681 | N/A | N/A | 194952 |
| 59 | Park Developments (dublin) LIMITED | Ireland | Dublin | The Herbert Building | Dublin | D18 K8Y4 | parkdevelopments.***** | 1968 | $111,138,593 | 65 | N/A | N/A | 27777 |
| 60 | Midland Steel Reinforcement Supplies LIMITED | Ireland | Portlaoise | Unit 21 | Laois | R32 NY77 | midlandsteelreinforcement.***** | 2000 | $108,445,872 | 157 | N/A | N/A | 354112 |
| 61 | Davenham Switchgear LIMITED | Ireland | Dublin | Unit 10 Weatherwell Industrial Estate | Dublin | D22 VP83 | N/A | 2000 | $105,401,533 | 258 | N/A | N/A | 320255 |
| 62 | Kilsaran Concrete Unlimited Company | Ireland | Dunboyne | Piercetown | Meath | A86 W820 | N/A | 1966 | $104,800,246 | 681 | N/A | N/A | 23927 |
| 63 | Designer Group Engineering Contractors LIMITED | Ireland | Dublin | Dublin Industrial Estate | Dublin | D11 V677 | designergrp.***** | 1992 | $101,434,843 | 419 | N/A | N/A | 196956 |
| 64 | Cfield Cs LIMITED | Ireland | Cork | 4th Floor | Cork | T12 RK0N | cfieldconstruction.***** | 2011 | $97,720,292 | 75 | N/A | N/A | 506472 |
| 65 | Purmo Group (UK) LTD | Ireland | Letterkenny | Glencar Shopping Centre | Donegal | F92 PCH9 | N/A | 2022 | $94,050,465 | 387 | N/A | N/A | 909807 |
| 66 | Gaffney Mechanical LIMITED | Ireland | Dublin | 1 Grants Row Lower Mount Street | Dublin | D02 HX96 | N/A | 2011 | $92,554,947 | 194 | N/A | N/A | 506525 |
| 67 | Fajon Construction LIMITED | Ireland | Dublin | Charter House | Dublin | D02 FW61 | N/A | 1990 | $89,896,931 | 54 | N/A | N/A | 161838 |
| 68 | Sensori Facilities Management LIMITED | Ireland | Dublin 15 | Plaza 211, Blanchardstown Corporate | Dublin | D15 AP2D | N/A | 2014 | $87,877,294 | 423 | N/A | N/A | 548567 |
| 69 | Brooks Timber & Building Supplies LIMITED | Ireland | Dublin | Old Naas Road | Dublin | D12 YXN2 | brooksonline.***** | 2012 | $87,488,418 | 136 | N/A | N/A | 509131 |
| 70 | Veolia Energy Ireland Public LIMITED Company | Ireland | Dublin | Suite 18 Plaza 256 | Dublin | D15TR96 | veolia.***** | 1999 | $82,927,192 | 364 | N/A | N/A | 314060 |
| 71 | Clancy Project Management LIMITED | Ireland | Thurles | Ballyluskey | North Tipperary | N/A | N/A | 2005 | $82,127,779 | 141 | N/A | N/A | 398496 |
| 72 | Murphy Process Engineering LIMITED | Ireland | Newbridge | Great Connell | Kildare | W12 HD61 | N/A | 1990 | $81,362,287 | 85 | N/A | N/A | 165132 |
| 73 | Cunningham Contracts (building And Civil Engineering) Ire LIMITED | Ireland | Dublin | Suite 5, Providence House Block 8a | Dublin | N/A | N/A | 2017 | $80,608,947 | 104 | N/A | N/A | 597172 |
| 74 | Carrickmines Manor LIMITED | Ireland | Dublin | Birmayne House | Dublin | D15A078 | N/A | 2005 | $80,036,464 | 119 | N/A | N/A | 402231 |
| 75 | Bellevarde LIMITED | Ireland | Donabate | Unit 12 Shannon Valley Centre | Dublin | N/A | N/A | 2012 | $78,085,461 | 6 | N/A | N/A | 515477 |
| 76 | K & J Townmore Construction LIMITED | Ireland | Tullamore | Clonminch House | Offaly | R35 A2Y4 | N/A | 2008 | $76,163,824 | 4 | N/A | N/A | 461199 |
| 77 | Sorensen Group Holdings LIMITED | Ireland | Cork | Unit 5 Westpoint Business Park | Cork | P31 K386 | N/A | 2013 | $76,096,037 | 156 | N/A | N/A | 525204 |
| 78 | Sorensen Civil Engineering LIMITED | Ireland | Cork | Unit 5 Westpoint Business Park | Cork | P31 K386 | sorensen.***** | 1977 | $76,070,658 | 156 | N/A | N/A | 59764 |
| 79 | Coffey Construction (i) LIMITED | Ireland | Athenry | Moanbaun | Galway | H65 Y078 | coffeyconstruction.***** | 2004 | $75,685,383 | 307 | N/A | N/A | 382121 |
| 80 | Clonmel Enterprises LIMITED | Ireland | Naas | Unit R | Kildare | W91 W64H | clonmelent.***** | 1974 | $74,997,223 | 97 | N/A | N/A | 48342 |
| 81 | Abm Contractors LIMITED | Ireland | Swords | Unit 2b Feltrim Business Park | Dublin | K67TX95 | N/A | 2011 | $74,435,273 | 76 | N/A | N/A | 505976 |
| 82 | M & P Construction LIMITED | Ireland | Saggart | Hillview | Dublin | D24 PKP0 | mpconstruction.***** | 1993 | $73,209,097 | 58 | N/A | N/A | 218393 |
| 83 | Duggan Profiles & Steel Service Centre LIMITED | Ireland | Kilkenny | Dublin Road | Kilkenny | R95 CCY5 | steel.***** | 1992 | $71,933,845 | 86 | N/A | N/A | 188195 |
| 84 | Kingspan Insulation LIMITED | Ireland | Castleblayney | Legal & Compliance Department | Monaghan | A75 X966 | kingspaninsulation.***** | 1976 | $71,769,104 | 121 | N/A | N/A | 54621 |
| 85 | Kwik Rc Frames LIMITED | Ireland | Westport | Dooega East | Mayo | F28 YE67 | N/A | 2015 | $71,202,707 | 6 | N/A | N/A | 555503 |
| 86 | Actavo (ireland) LIMITED | Ireland | Dublin | Westland Park | Dublin | N/A | N/A | 1985 | $69,141,369 | 353 | N/A | N/A | 105844 |
| 87 | Homeland Projects LIMITED | Ireland | Dublin | 38 Palmerston Road | Dublin | D06 YW68 | N/A | 2002 | $68,776,691 | 28 | N/A | N/A | 357086 |
| 88 | William Neville & Sons Construction Unlimited Company | Ireland | Wexford | Riversfield House | Wexford | Y35 E6P1 | williamneville.***** | 1968 | $68,501,145 | 137 | N/A | N/A | 192941 |
| 89 | King And Moffatt Ireland LIMITED | Ireland | Carrick-on-shannon | Attirory Roundabout | Leitrim | N41 XE89 | N/A | 1978 | $66,858,735 | 234 | N/A | N/A | 171584 |
| 90 | Glenbrier LIMITED | Ireland | Navan | Dunmoe Lodge | Meath | C15 W4A8 | glenbrier.***** | 1996 | $66,735,369 | 110 | N/A | N/A | 242948 |
| 91 | Dalata LIMITED | Ireland | Dalkey | Coliemore House | Dublin | N/A | N/A | 2007 | $65,105,215 | 386 | N/A | N/A | 441276 |
| 92 | Virgin Media Television LIMITED | Ireland | Ballymount | Unit 5, Westgate Business Park | Kildare | D24 PX61 | tv3.***** | 1997 | $64,316,074 | 275 | N/A | N/A | 272612 |
| 93 | Evara Developments LIMITED | Ireland | Dublin | Fitzwilliam Court | Dublin | D02 YW24 | N/A | 2019 | $63,607,393 | 63 | N/A | N/A | 656280 |
| 94 | Castle Electrical Factors LIMITED | Ireland | Dublin | 94/96 Middle Abbey Street | Dublin | D01 W8N7 | cefltd.***** | 2007 | $62,924,662 | 98 | N/A | N/A | 438619 |
| 95 | James Stewart LIMITED | Ireland | Galway | 43 Salthill Road Lower | Galway | H91 A6Y7 | stewart.***** | 1938 | $62,693,579 | 64 | N/A | N/A | 9621 |
| 96 | Jsl Group LIMITED | Ireland | Galway | 43 Lower Salthill | Galway | H91 A6Y7 | stewart.***** | 1984 | $62,553,661 | 62 | N/A | N/A | 104723 |
| 97 | Cumnor Construction LIMITED | Ireland | Cork | Stoneview | Cork | T23 YN60 | cumnor.***** | 1970 | $60,173,709 | 106 | N/A | N/A | 30446 |
| 98 | Kingspan Tate LIMITED | Ireland | Dublin | Units | Dublin | D10 KH30 | N/A | 2017 | $59,170,950 | 103 | N/A | N/A | 616406 |
| 99 | Brian M. Durkan & CO. LIMITED | Ireland | Dun Laoghaire | 63 York Road | Dublin | A96 T0H4 | bmdurkan.***** | 1993 | $58,898,116 | 31 | N/A | N/A | 204636 |
| 100 | Ucd Property Development Company LIMITED | Ireland | Dublin | School of Veterinary Medicine | Dublin | N/A | N/A | 2000 | $58,639,487 | 7 | N/A | N/A | 328862 |