Largest Consulting Firms (2026)

Deloitte is the largest professional-services network in the world by revenue. It reported aggregate revenue of US$74.5bn for the fiscal year ended 31 May 2026, up 5.7% in US dollars and 3.8% in local currency. Its global workforce is nearly 500,000 people in more than 150 countries and territories. Deloitte is organised as a network: Deloitte Touche Tohmatsu Limited coordinates the member firms but does not itself provide services to clients, and each member firm is a legally separate entity. Revenue covers audit and assurance, tax and legal as well as consulting and advisory work.

Accenture is the largest listed company on this list. It reported revenue of US$74.2bn for the fiscal year ended 31 August 2026, an increase of 6% in US dollars and 5% in local currency, placing it marginally behind Deloitte on a different fiscal calendar. The company had approximately 814,000 people at the end of the year. Fortune lists Accenture under Ireland, with Dublin as its headquarters city, and names Julie Sweet as chief executive. Unlike the Big Four, Accenture has no audit practice.

PwC is the second-largest of the Big Four accounting and advisory networks. Its member firms reported gross revenue of US$60.2bn for the fiscal year ended 30 June 2026, up 5.7% in US dollars and 3.5% at constant exchange rates. The figures were announced on 19 October 2026. Advisory revenue grew 3.0% at constant exchange rates, slower than the network as a whole. Like the other Big Four networks, PwC combines statutory audit with consulting, deals and tax work, and the total is not a pure consulting figure.

EY reported combined global revenue of US$56,969m for the fiscal year ending June 2026, up 4.7% in local currency from US$53,219m. Its consulting service line generated US$17,430m and its strategy and transactions arm, EY-Parthenon, US$6,836m; assurance, at US$18,905m, remained the largest single line. EY had 415,182 people at the end of June 2026 and provides services in more than 150 countries and territories. Its five-year compound annual growth rate was 8.3%.

KPMG is the smallest of the Big Four by revenue. It reported US$39.8bn for the fiscal year ended 30 September 2025 on a continued-operations basis, up 5.4% in US dollars and 5.1% in local currency; on a full basis the figure was US$40.2bn. Advisory revenue was US$16.4bn, up 2.9% in local currency. KPMG had 276,030 people and its member firms operate in 138 countries and territories. This list uses KPMG's fiscal 2025 figures, the latest found during compilation.

The group listed in the Fortune 500 as Marsh & McLennan now presents itself as Marsh, trading under the ticker MRSH, and describes itself as a global leader in risk, reinsurance and capital, people and investments, and management consulting. Its businesses include the Mercer and Oliver Wyman consulting brands alongside insurance broking. Fortune records revenue of US$27.0bn, up 10.3%, with 95,000 employees, and classifies the group under diversified financials rather than consulting. Only part of its revenue therefore comes from consulting.

Capgemini is the largest company on this list headquartered in continental Europe. Fortune records fiscal 2025 revenue of US$25.3bn, up 6.04% in dollar terms, and 423,405 employees. The company is based in Paris and led by Aiman Ezzat, according to its Fortune profile. Fortune classifies it under information technology services.

Cognizant Technology Solutions provides IT consulting, digital engineering and outsourcing services. Fortune records revenue of US$21.1bn, up 7%, and a workforce of 351,600, one of the largest of any US company. The company is headquartered in Teaneck, New Jersey. Fortune classifies it under information technology services.

Leidos describes itself as an industry and technology leader providing digital and mission solutions to government and commercial clients. Most of its work is technical and engineering services rather than advisory consulting, but Fortune classifies it with IT services companies. Fortune records revenue of US$17.2bn, up 3.1%, and 47,000 employees. The company is headquartered in Reston, Virginia.

AECOM provides design, engineering, program-management and consulting services for infrastructure owners. Its Fortune figures are for the fiscal year ended 30 September 2025 and include revenues from discontinued operations. Revenue was US$16.2bn, down 0.3%, and the firm employs 51,000 people. Fortune classifies AECOM under engineering and construction, and it also appears in rankings of the largest construction companies.

Boston Consulting Group is the largest strategy-focused management consultancy on this list. It reported global revenue of US$14.4bn for 2025, up 7% from US$13.5bn in 2024, its 22nd consecutive year of growth. The firm employed 33,500 people at the end of 2025 and has offices in more than 100 cities in over 50 countries. BCG is not listed on a stock exchange, so its figures are not subject to public-company reporting rules.

Jacobs provides engineering, consulting and project-delivery services, for public and private clients. Its Fortune figures are for the fiscal year ended 30 September 2025, and Fortune notes that the company spun off Amentum Holdings on 27 September 2024. Revenue was US$12.0bn, down 29.1% on the figure originally reported for the prior year, and Jacobs employs 42,100 people. It is headquartered in Dallas.

Booz Allen Hamilton provides management and technology consulting, mainly to US government agencies. Fortune records revenue of US$12.0bn, up 12.4%, for the fiscal year ended 31 March 2025, and 35,800 employees. The company is headquartered in McLean, Virginia, and Fortune names Horacio D. Rozanski as chief executive. Its revenue was about US$50m below that of Jacobs on Fortune's figures.

Atos is a French IT services and consulting group headquartered in Bezons. Fortune records fiscal 2025 revenue of US$9.0bn, down 12.87%, the steepest decline among the companies on this list apart from Jacobs. It employs 63,193 people. Fortune classifies Atos under information technology services.

Gartner sells research subscriptions, conferences and consulting to business and IT leaders. Fortune records revenue of US$6.5bn, up 3.7%, and 20,244 employees. The company is headquartered in Stamford, Connecticut. It is included as a research and advisory firm rather than a pure consultancy.

EPAM Systems provides software engineering, digital-platform and consulting services. Fortune records revenue of US$5.5bn, up 15.4%, one of the fastest growth rates on this list, and 62,850 employees. Its Fortune entry gives Newtown, Pennsylvania, as headquarters city.

Tetra Tech provides consulting and engineering services focused on water, environment and infrastructure. Its Fortune figures are for the fiscal year ended 30 September 2025. Revenue was US$5.4bn, up 4.7%, and the company employs 25,000 people. It is headquartered in Pasadena, California.

FTI Consulting advises companies on restructuring, disputes and investigations, economic analysis, and strategic communications. Fortune records revenue of US$3.8bn, up 2.4%, and 8,118 employees. The firm is headquartered in Washington, D.C. At about US$467,000, its revenue per employee is the highest of any firm on this list for which Fortune reports both revenue and headcount.

Korn Ferry combines organisational consulting, executive search and recruitment process outsourcing. Fortune records revenue of US$2.8bn, down 1.2%, for the fiscal year ended 30 April 2025, and 9,253 employees. The firm is headquartered in Los Angeles.

CBIZ provides accounting, tax, advisory and benefits services, mainly to mid-sized businesses. Fortune records revenue of US$2.76bn, up 52.1%, the fastest growth on this list, and 9,500 employees. Its revenue was about US$3m below Korn Ferry's on Fortune's figures. Fortune gives Independence, Ohio, as its headquarters city.