Jacques Tits (born August 12, 1930, Uccle, Belgium—died December 5, 2021, Paris, France) was a Belgian-born French mathematician who was awarded the 2008 Abel Prize by the Norwegian Academy of Sciences and Letters, which cited him for having “created a new and highly influential vision of groups as geometric objects.”
Tits, the son of a mathematician, passed the entrance exam to the Free University of Brussels at age 14. In 1950 he earned a doctorate from that institution, where he stayed to teach until 1964, when he moved to the University of Bonn in West Germany. In 1973 he accepted the chair of group theory at the Collège de France in Paris, where he remained until his retirement in 2000. Tits became a French citizen in 1974, the same year that he became a member of the French Academy of Sciences. In awarding him the Abel Prize, the academy noted especially that “he introduced what is now known as a Tits building, which encodes in geometric terms the algebraic structure of linear groups.”
In addition to his teaching and research, Tits was the editor in chief for mathematical publications at the Institut des Hautes Études Scientifiques (1980–99) near Paris and served on the committees that awarded the Fields Medals in 1978 and 1994. Among dozens of other awards, in 1993 Tits received the prestigious Wolf Prize in Mathematics, an annual international award presented in recognition of outstanding work in the field of mathematics.