Born on 24 March 1893 in Florence into a noble family, Brilli-Peri received the title of Count. His face had been permanently scarred in an accident during a Tour of Italy motorcycle race, and he became recognisable on the circuits of the 1920s for wearing a distinctive hat resembling a Basque beret — a headgear that has since become known in Italy as a brilliperi in his honour.
He showed early sporting ambition: he debuted in a bicycle race in 1907 at the age of 14 and won the Tuscan cycling championship in 1911. In 1912 he acquired a motorcycle and in 1914 debuted in a motorcycle race at Lake Trasimeno, winning the first Motogiro of Italy in the same year. He first raced a car just after the First World War, having served as a motorcycle rider during the conflict.
Brilli-Peri's defining moment came in 1925 at Monza during the Italian Grand Prix, the final event of the inaugural season of the World Manufacturers' Championship. Driving an Alfa Romeo P2, he won the race outright. Alfa Romeo's accumulated results across the season were sufficient to claim the manufacturers' title — the first such world championship in motor racing history — and Brilli-Peri's Monza victory was central to that achievement.
In 1929, still competitive in an Alfa Romeo P2 that was by then several years old, he won the Circuit of Cremona and the Tripoli Grand Prix in Italian Libya — results that demonstrated both his skill and the continuing competitiveness of the Alfa Romeo P2 in the right hands.
Brilli-Peri was killed on the morning of Saturday 22 March 1930 during free practice for the sixth Tripoli Grand Prix. Practice had been scheduled from 11am to 1:50pm. Knowing the circuit well from his victory the previous year, Brilli-Peri arrived to test cars for his team, the Scuderia Materassi. He completed one lap in his own car, then switched to the car of his teammate Clemente Biondetti, which was suffering carburation problems, before returning to his own Talbot for another run.
During his second lap in the Talbot, negotiating a fast left-handed bend near the village of Suq al Jum'ah, the car bounced on the irregular road surface and Brilli-Peri lost control. The car struck the right embankment and he was ejected, dying on impact. The time was approximately 12:50pm. He was 37 years old, two days short of his birthday.
The Stadio Brilli-Peri in Montevarchi, his birthplace, is named in his honour. The Italian actress Nancy Brilli is his niece. Brilli-Peri's career occupies an important place in the early history of organised world championship racing: his 1925 Monza win was the decisive contribution to Alfa Romeo securing the very first FIA-recognised World Manufacturers' Championship, a context that gives his sole Grand Prix victory a significance beyond its headline result.