| Firm | Origin | Global Headquarters | Est. Global Revenue (FY2023) | Global Presence (Countries) |
| McKinsey & Co. | 1926, USA | New York City, USA | ~$16 Billion | 65+ |
| Boston Consulting Group (BCG) | 1963, USA | Boston, USA | ~$12.3 Billion | 50+ |
| Bain & Company | 1973, USA | Boston, USA | ~$6.4 Billion | 40 |
| Deloitte Consulting | 1845, UK | New York City, USA | Part of $64.9 Billion total revenue | 150+ |
| PwC Advisory (Strategy&) | 1998, UK | London, UK | Part of $53.1 Billion total revenue | 151 |
| EY Advisory (EY-Parthenon) | 1989, UK | London, UK | Part of $49.4 Billion total revenue | 150+ |
| KPMG Advisory | 1987, Netherlands | Amstelveen, Netherlands | Part of $36.4 Billion total revenue | 143 |
| Accenture | 1989, USA | Dublin, Ireland | $64.1 Billion | 120+ |
| Kearney | 1926, USA | Chicago, USA | ~$1.5+ Billion | 40+ |
| Oliver Wyman | 2007, USA | New York City, USA | ~$3.1+ Billion | 30 |
(Revenue for Deloitte, PwC, EY, and KPMG represents the entire firm’s revenue, of which their consulting/advisory arms are a major part. Revenues for private firms are industry estimates.)