Tombazis is the son of prominent Greek architect Alexandros Tombazis and grandson of geologist and photographer N. A. Tombazi. His passion for Formula One was ignited around age ten by the ground-effect Lotus 78 and Lotus 79, and as a school project he wrote a five-page essay about Lotus founder Colin Chapman. He earned an engineering degree with an aerodynamics specialisation from Trinity College, Cambridge in 1989, followed by a PhD in aeronautical engineering from Imperial College London in 1992. It was at Cambridge that he first met James Allison, a future colleague at Ferrari.
Tombazis joined Benetton as an aerodynamicist in November 1992 after McLaren declined to hire him. He was promoted to chief aerodynamicist by 1993 and head of aerodynamics by 1994. Working alongside technical director Ross Brawn and designer Rory Byrne, he contributed to the Benetton B194 that gave Michael Schumacher his first Drivers' Championship. The following year the improved B195 swept both the Drivers' and Constructors' titles, partially vindicating the team from the controversy surrounding 1994. When Brawn and Byrne followed Schumacher to Ferrari for 1997, Tombazis went with them.
At Maranello, Tombazis eventually rose to head of aerodynamics and CFD in 1999, replacing Willem Toet. He was part of the core group responsible for Ferrari's era of dominance: the team won five consecutive Constructors' Championships from 1999 to 2003 and Schumacher took four consecutive Drivers' titles from 2000 to 2003. The 2000 title — Ferrari's first Drivers' crown since 1979 — was later described by Tombazis as "the real special moment." After wanting a new challenge, he left for McLaren at the end of 2003.
Tombazis joined McLaren as chief aerodynamicist and head of planning. He contributed to the McLaren MP4-19B, which salvaged results after the troubled MP4-19, and played a meaningful role in the MP4-20 that challenged Renault's Fernando Alonso for the 2005 championship, winning ten races but finishing nine points behind. He was promoted to director of vehicle projects in April 2005, effectively becoming chief designer. Missing the Maranello environment, he agreed to return to Ferrari.
Back at Ferrari as chief designer from March 2006, Tombazis immediately achieved a major result: the F2007 carried Kimi Räikkönen to the Drivers' title in one of Formula One's most dramatic late-season comebacks, while Ferrari also won the Constructors' crown. The F2008 brought another Constructors' title, though Felipe Massa was narrowly beaten on the last lap of the final race. The years 2009–2013 proved far more difficult; Ferrari struggled with diffuser and aerodynamic coherence issues, and the team could not match Red Bull or Mercedes despite Fernando Alonso taking the championship fight to the final round in both 2010 and 2012. Tombazis departed in December 2014 as part of a broader technical reshuffle. In later interviews he expressed frustration at being seen as a scapegoat, pointing out he had worked significantly on the more competitive SF15-T that raced after his exit.
After a year on gardening leave, Tombazis joined Manor Racing as chief aerodynamicist in January 2016. He oversaw significant improvement in the 2016 car, which scored a single point, and worked on a reportedly competitive 2017 project before Manor was closed in March 2017 due to financial difficulties. He then set up his own consultancy, MAA, and accepted a visiting professorship in aerodynamics at Imperial College London.
In 2018 Tombazis joined the FIA as head of single-seater technical matters, working under technical director Gilles Simon. He was the principal architect of the 2022 regulations that reintroduced ground effect to Formula One with the stated goals of reducing dirty air, enabling closer racing, and lowering team costs. The regulations delivered a more closely contested grid, particularly in 2024–2025, but developed shortcomings including the re-emergence of dirty air, DRS trains, and flexi-wing controversies. Tombazis acknowledged in December 2025 that the regulations did not fully deliver their promises.
In January 2023 he was promoted to single seater director. The 2026 regulations, developed under his direction, introduced active aerodynamics (X-mode for low drag, Z-mode for high downforce), a revised power unit formula balancing internal combustion and electric power, smaller and lighter cars, and a driver-controlled boost system replacing DRS. When the 2026 cars raced, new problems emerged including super clipping — abrupt power loss at the end of straights when the electric battery depleted — and driver dissatisfaction. Tombazis defended the framework while acknowledging specific areas requiring adjustment, and targeted modifications were introduced ahead of the 2026 Miami Grand Prix.
Across his career as a designer, Tombazis contributed to championship-winning cars that secured seven Drivers' Championships and eight Constructors' Championships. His 84 race wins from 151 Grands Prix as a contributing designer places him among the most decorated aerodynamicists in Formula One history. As an FIA official he has shaped two of the sport's most technically ambitious regulation cycles, with the 2022 framework generally credited with reviving grid competitiveness even as its limitations were debated.