Senna was raised in São Paulo by his mother Viviane, Ayrton's sister. He began karting at age five on the family farm, taught partly by his grandfather and uncle Ayrton, who spoke highly of the young Bruno's potential. Ayrton's death at the 1994 San Marino Grand Prix brought Bruno's racing to a halt for nearly a decade; the added loss of his father in a motorbike accident in 1996 compounded the disruption. Senna eventually returned to motorsport, contesting six Formula BMW UK races in 2004 before advancing to British Formula Three in 2005 with the Räikkönen Robertson Racing team.
In 2005, Senna joined the team co-owned by McLaren driver Kimi Räikkönen and earned three podiums across the final stretch of the season. In 2006 he stepped up decisively, winning five races and finishing third in the championship behind champion Mike Conway and Oliver Jarvis. His performances included victory in the opening two rounds at Oulton Park in wet conditions and a notable win at Donington Park. That same year he competed in the Formula Three support races at the Australian Grand Prix weekend, winning three of the four races and setting a Formula Three lap record of 1:50.864 at Melbourne that stood as the fastest ever non-F1 lap of the circuit for years.
Senna entered the GP2 Series in 2007 with the Red Bull-backed Arden International team. He scored his first GP2 feature-race win in Spain and collected a total of one victory and three podiums in his debut campaign, finishing inside the top ten of the standings in only his third full season of single-seater racing.
For 2008 he switched to iSport International, where his teammate was Karun Chandhok. The season also included the GP2 Asia Series, during which Senna retired from a sprint race at Istanbul after colliding with a stray dog that had wandered onto the circuit. In the main GP2 campaign he delivered a landmark result by winning the feature race at Monaco, the first time the Senna name had topped the results at the principality since his uncle's era. The Monaco win propelled him to first in the championship standings.
The title fight with Giorgio Pantano swung back and forth across the summer. After losing ground through retirements in Monaco's sprint race and at other rounds, Senna headed into the season finale at Monza holding a deficit. Pantano clinched the championship there, finishing tenth, while Senna came fifth — enough for Pantano but leaving Senna as runner-up in the final standings.
Despite missing out on the GP2 crown, Senna used the 2008 runner-up finish as a platform toward Formula One. He tested for Honda in Barcelona in November 2008 and came within 0.3 seconds of then-Honda race driver Jenson Button. After Honda's withdrawal from the sport, Senna eventually secured a race seat with HRT for 2010, then drove for Renault from mid-2011 and Williams across the full 2012 season. He scored 31 championship points in his final Formula One campaign and recorded the fastest lap at the 2012 Belgian Grand Prix.
Beyond Formula One, Senna built a successful endurance racing career. Driving for Mahindra in Formula E from 2014 to 2016, he then joined Rebellion Racing in the FIA World Endurance Championship. In 2017, sharing the Rebellion No. 13 LMP2 car with Julien Canal and Nico Prost, he won the FIA Endurance Trophy in the LMP2 class at the season finale in Bahrain — muscling the car home for the final 50 minutes of the race without power steering to secure both the race win and the championship.
Senna navigated the dual burden of a famous surname and a decade-long interruption to his career with considerable persistence. His 2006 Formula Three season in Australia demonstrated raw speed, his 2008 Monaco GP2 win carried emotional weight given his family's history at the circuit, and his 2017 WEC title confirmed him as a genuine competitor beyond the junior formulae. He later expanded into media work as a Formula One pundit for Sky Sports F1 and Channel 4, and moved into emerging motorsport formats including the Airspeeder eVTOL racing series from 2022.