Their story
Our story begins with our purpose: making an impact that matters. Our founder, William Welch Deloitte, understood this well. In 1845, he had a vision to build something that would last.
Understanding the power of connection, collaboration, and innovation, he established Deloitte as a small accountancy firm. And because of his legacy, Deloitte has grown into a thriving global organization of more than 470,000 people who are dedicated to changing the world.
These founding beliefs have driven our growth for over 180 years and are the bedrock of today's Deloitte and our goal of solving the world's greatest challenges—in business and society.
Deloitte also has a long history in Luxembourg. What started in the 1950s as a small accountancy practice, “l'Agence,” is today a multidisciplinary firm of more than 2,600 employees. Deloitte Luxembourg celebrated its 75th anniversary in 2025.