Belgian violinist noted for both his performing and his teaching.

Grumiaux studied at the Charleroi and Royal conservatories in Brussels and later with Georges Enescu in Paris. In 1939 he won the Vieuxtemps Prize, and a year later he became the first recipient of the Belgian government's Prix de Virtuosité. Shortly after his debut in Brussels in 1940, his career was halted by the German occupation of Belgium. He began performing again in 1945, making his London debut that year, and rapidly became known in Europe and the United States. In 1949 he succeeded his former teacher, Alfred Dubois, at the Brussels Conservatory. Especially notable among his recordings are the unaccompanied J.S. Bach sonatas and the sets of Ludwig van Beethoven and W.A. Mozart sonatas (with pianist Clara Haskil). His playing combined refined elegance with an accomplished technique. Belgium awarded him a barony in 1973.