Born in Montreal and of Italian origin, he learned artistic decoration of murals and stained glass at the age of 13 from stained glass artist Guido Nincheri. He was also a professor at the Académie Querbes, located in Outremont, in 1939. Nine years later, he became a teacher there and held his post until 1969.
He will be known in his career for having decorated many Catholic religious buildings across Quebec and for his bust of Brother André, made a few months after his death in 1937. Bruni also organized various symposiums and individual exhibitions . He was a member of the International Institute for Conservation, the Academia Gentium 'Pro Pace', the Royal Canadian Academy of Arts and the Institute of Figurative Arts and has made over 30 "solo" exhibitions.
Umberto Bruni died in Laval on February 1, 2021 at the age of 106.