Masi was born in Sydney, Australia, in 1978 and is of Italian descent. Growing up in the suburbs of Fairfield and Canada Bay, he attended Patrician Brothers' College. He initially studied marketing at TAFE before his roles in motorsport.
Masi began his career in motor racing volunteering for Super Touring teams while still at school. He worked as deputy race director in the Supercars touring car racing series and at Rally Australia. In 2018, he was appointed by the FIA as the Formula 2 and Formula 3 deputy race director, and was appointed deputy to F1 race director Charlie Whiting. Masi alternated in this role between Grands Prix with Scot Elkins.
Following Whiting's death before the 2019 Australian Grand Prix, Masi took on the role of Formula One race director. Several of his decisions as race director were subject to scrutiny. During the 2020 Turkish Grand Prix qualifying session, cars were sent out on track while a crane was still on the track. In the 2021 season, he was required to defend the red flag procedures used during the 2021 Azerbaijan Grand Prix. He was criticised for running qualifying in dangerous conditions during the 2021 Belgian Grand Prix and for negotiating with teams during the 2021 Saudi Arabian Grand Prix.
Masi’s handling of the safety car period during the final lap of the 2021 Abu Dhabi Grand Prix was subject to debate. The FIA official report into the controversy confirmed regulation infringements, specifically that “the Race Director called the safety car back into the pit lane without it having completed an additional lap as required by the Formula 1 Sporting Regulations (Article 48.12)”. The report concluded that Masi incorrectly applied regulations, in that not all lapped cars had unlapped themselves, and the safety car had not completed the mandatory additional lap before returning to the pitlane. The FIA official report attributed these matters to "human error".
Masi was removed from his role as Race Director on 17 February 2022, following the FIA investigation into the Abu Dhabi Grand Prix. He was replaced by Niels Wittich and Eduardo Freitas. A new position within the FIA as the Independent Chair of the Supercar Commission was offered to Masi, which he took in August 2022. In July 2022, Masi left the FIA to return to Australia and spend more time with his family. In September, he was appointed the independent Chairman of the Supercars Commission in Australia, a role he held until September 2025. He was appointed to the board of directors of Karting Australia in December. In December 2025, Masi was appointed as the Event Director for the Repco NextGen NZ Championship, which includes the Formula Regional Oceania Trophy.
Due to abuse and death threats received after the Abu Dhabi Grand Prix, and exhaustion from travelling as race director, Masi sought help with his mental health. During the 2023 Australian Grand Prix, Masi sought to meet with Lewis Hamilton to explain his decisions during the 2021 Abu Dhabi Grand Prix. Hamilton declined the meeting, stating there was “nothing to say”. Masi’s decisions in the 2021 Abu Dhabi Grand Prix contributed to Mohammed Ben Sulayem’s FIA Presidential campaign platform, which emphasized restructuring and modernising race operations, with Ben Sulayem believing changes were necessary to restore public trust.
This article is based solely on the supplied corpus. No primary archives, autobiographies, period programmes, or specialist publications were consulted.