Deloitte
World's largest professional services and accounting network by revenue, serving clients across 150+ countries.
Deloitte Global Revenue Announcement (Official Press Room)Deloitte is one of the "Big Four" global professional services firms and the largest accounting organization in the world by revenue. Founded by William Welch Deloitte in London in 1845 and expanded into the United States in 1890, it grew through major mergers — including with Haskins & Sells (1952), Touche Ross (1989), and portions of Arthur Andersen (2002) — into its current form as a network of member firms operating under Deloitte Touche Tohmatsu Limited (DTTL), a private company limited by guarantee incorporated in England and Wales.
The firm provides services across Audit & Assurance, Consulting, Tax, and Risk & Financial Advisory in over 150 countries, with more than 700 offices and a global workforce exceeding 460,000 people as of 2024. Consulting has become its largest revenue segment. Deloitte reported aggregate global revenue of US$70.5 billion for FY2025 (ending 31 May 2025), a 4.8% increase in local currency year-on-year, cementing its position ahead of PwC, EY, and KPMG.
Under Global CEO Joe Ucuzoglu, Deloitte has emphasized next-generation capabilities, including expansion of its "Operate" managed business process outsourcing services with industry-specific offerings in Electronic Health Records, Software-defined Vehicles, and Supply Chain Resilience. In 2024, Deloitte joined Nvidia, Microsoft, and AWS in a combined $40 million funding initiative for the Cancer AI Alliance, reflecting its broader investment in AI-driven solutions.
As a firm operating at this scale across consulting, technology, and advisory services, Deloitte is both a significant adopter and an active promoter of innovations in areas such as artificial intelligence, digital transformation, and managed services — making it directly relevant to any emerging capability in enterprise technology or professional services.