D aniel Roullier is a French self-made billionaire and the founder of Groupe Roullier, a major international player in the field of plant, animal, and human nutrition. He founded the company in 1959 in Saint-Malo, France, initially focusing on grinding seashell deposits to create calcium-rich soil amendments for local farmers.

From this modest beginning, he built a global agribusiness giant. The company has become a leader in producing high-tech fertilizers and specialized nutritional products for agriculture. The group has diversified its operations significantly and is now a major supplier of a wide range of products for the food industry. Despite its global scale, the company remains privately owned by the Roullier family. After leading the company for over 50 years, Daniel Roullier has passed on the day-to-day management to his children and grandchildren, but he remains the patriarch of the successful family enterprise he built from scratch.