The following is a list of the largest information technology consulting firms in the world, along with their corporate headquarters location and the total number of consultants they have. Many of these serve primarily as third-party consultants. Many enterprise software companies employ their own consultants for services related to their own products. Among the corporations listed below, the number of consultants listed is less than their total number of employees.
Note: Not all employees of these firms are consultants and firms with less than 10,000 employees are not included.
By continent
Asia
| Name | Headquarters | Total company employees | As of |
| Fujitsu | Tokyo, Japan | 155,000 | 2017[1] |
| HCL Technologies | Noida, India | 119,291 | December 2017[2] |
| Hexaware | Navi Mumbai, India | 12,734 | March 2017 |
| Infosys | Bangalore, India | 200,364 | March 2017 |
| Larsen & Toubro Infotech | Mumbai, India | 21,023 | March 2017 |
| Mphasis | Bangalore, India | 21,994 | March 2017 |
| UST Global | Trivandrum, India | 17,000 | March 2017 |
| Mindtree | Bangalore, India | 19,000 | March 2018[3] |
| Neusoft Group | Shenyang, China | 15,000 | |
| NIIT Technologies | Noida, India | 9,476 | |
| NTT Data | Tokyo, Japan | 100,000 | |
| Pactera | Beijing, China | 23,954 | |
| Tata Consultancy Services | Mumbai, India | 387,223 | March 2017 |
| Tech Mahindra | Pune, India | 117,693 | March 2017 |
| Wipro | Bangalore, India | 181,482 | March 2017 |
| WNS Global Services | Mumbai, India | 33,968 | March 2017 |
Europe
| Name | Headquarters | Total company employees | As of |
| Accenture | Dublin, Ireland | 449,000 | September 2018 [4] |
| Alten | Boulogne-Billancourt, France | 24,000 | 2016 |
| Altran | Paris, France | 44,000 | December 2017 [5] |
| Atos | Paris, France | 100,000 | 2015 |
| Capgemini | Paris, France | 205,600 | June 2018 [6] |
| Deloitte Touche Tohmatsu | London, England | 203,000 | |
| EVRY | Oslo, Norway | 10,000 | |
| Indra | Madrid, Spain | 34,000 | |
| KPMG | Amstelveen, Netherlands | 188,982 | 2016 [7] |
| PWC | London, England | 184,000 | |
| Ernst & Young |
London, England |
250,000 |
2017[8] |
| T-Systems | Frankfurt, Germany | 48,200 | |
| Tieto | Espoo, Finland | 15,000 | |
| Sogeti | Paris, France | 20,000 | |
| Sopra Steria | Paris, France | 37,000 | |
North America
| Name | Headquarters | Total company employees | As of |
| Avanade | Seattle, WA | 29,000 | 2016[9] |
| Booz Allen Hamilton | McLean, VA | 23,000 | |
| CGI Group | Montreal, Quebec, Canada | 69,000 | September 2013 [10] |
| Cognizant Technology Solutions | Teaneck, NJ | 261,200 | |
| Conduent | Florham Park, New Jersey | 92,000 | |
| DXC Technology | Tysons, VA | 170,000 | |
| EPAM Systems | Newtown, PA | 22,383 | |
| Gartner | Stamford, Connecticut | 15,000 | |
| Genpact | Hamilton, Bermuda | 68,000 | January 2015 |
| HP Enterprise Services | Palo Alto, CA | 176,000 | |
| IBM Global Business Services | Armonk, NY | 190,000 | |
| Softtek | Monterrey, Nuevo Leon, Mexico | 12,000 | |
| Syntel | Troy, Michigan | 24,333 | September 2014 [11] |
| Science Applications International Corporation | Reston, Virginia | 15,000 | |
| Unisys | Blue Bell, PA | 31,000 | |