20th-century Belgian inventors

Georges Cuisenaire (1891–1975), also known as Emile-Georges Cuisenaire, was a Belgian teacher who invented Cuisenaire rods, a mathematics teaching aid.

Frédéric Jean Edmond Swarts (2 September 1866 – 6 September 1940) was a Belgian chemist who prepared the first chlorofluorocarbon, CF2Cl2 (Freon-12) as well as several other related compounds. He was a professor in the civil engineering at the University of Ghent. In addition to his work on organofluorine chemistry, he authored the textbook "Cours de Chimie Organique." He was a son of Theodore Swarts (chemist, *1839 Antwerpen; †1911 Kortenberg, Belgium) and a colleague of Leo Baekeland.

Paul Adriaan Jan, Baron Janssen (12 September 1926 – 11 November 2003) was a Belgian physician. He was the founder of Janssen Pharmaceutica, a pharmaceutical company with over 20,000 employees which is now a subsidiary of Johnson & Johnson.