Hill was born in Hampstead, London, the son of a stockbroker. He studied engineering at Hendon Technical College and worked at Smiths Instruments before completing national service in the Royal Navy, serving as an Engine Room Artificer on the light cruiser HMS Swiftsure. Before motor racing he was an active competitive rower, joining London Rowing Club in 1952 and competing in 20 finals over two years, often as stroke of the crew. He rowed in the prestigious Grand Challenge Cup at Henley Royal Regatta, losing a semi-final to a French club by a length. He credited the discipline and determination learned through rowing as formative attributes in his racing career, and adopted the dark blue and white oar design of London Rowing Club for his racing helmet, a design his son Damon and grandson Josh later continued.
Hill did not pass his driving test until he was 24. In 1954 he saw an advertisement offering laps at Brands Hatch for five shillings, made his debut in a Cooper 500 Formula Three car, and was immediately committed to racing. He joined Team Lotus as a mechanic and talked his way into a cockpit, debuting at the 1958 Monaco Grand Prix.
In 1960 Hill joined BRM. The team fielded the competitive P57 for 1962, and Hill took his maiden victory at the Dutch Grand Prix before adding three more wins in the season to claim his first World Drivers' Championship over Jim Clark and Bruce McLaren. He finished runner-up to Clark in 1963 and lost the 1964 championship to John Surtees by a single point, then again finished second to Clark in 1965.
After a winless 1966 season at BRM — during which he won the Indianapolis 500 at his first attempt in a Lola-Ford, setting a record as the first rookie winner since 1927 — Hill returned to Lotus to partner Clark.
In 1967, Hill helped develop the Lotus 49 around the new Cosworth DFV engine, performing the initial shakedown runs. After Clark and Mike Spence were both killed in early 1968, Hill led the team through a close title fight with Jackie Stewart, ultimately winning the Drivers' Championship at the final race of the season. In 1969 he became a five-time winner of the Monaco Grand Prix, a record he held for 24 years. Later that year, at the United States Grand Prix at Watkins Glen, Hill crashed and broke both legs, ending his season.
After recovering from his leg injuries, Hill returned as a privateer in 1970, then competed with Brabham for 1971–72. His last Formula One win was the non-championship BRDC International Trophy at Silverstone in 1971 in the distinctive "lobster claw" Brabham. As his single-seater career wound down, Hill became a central part of the Matra sports car programme, and in 1972 co-drove a Matra-Simca MS670 with Henri Pescarolo to victory at the 24 Hours of Le Mans — completing the Triple Crown of Motorsport. He remains to this day the only person to have done so.
Hill founded his own team, Embassy Hill, in 1973 with sponsorship from Imperial Tobacco, running Shadow and Lola chassis before developing their own design. After failing to qualify for the 1975 Monaco Grand Prix — the race he had won five times — Hill retired from driving to focus on team ownership and supporting his young protégé Tony Brise.
On 29 November 1975, Hill was piloting his Piper PA-23 Aztec on a night approach to Elstree Airfield in thick fog, returning from a test session at the Circuit Paul Ricard in France. The aircraft crashed near Arkley in the London Borough of Barnet. Hill, Brise, team manager Ray Brimble, mechanics Tony Alcock and Terry Richards, and designer Andy Smallman were all killed. Hill was 46.
Subsequent investigation found that Hill's aircraft had been removed from the FAA register and was unregistered at the time of the crash, and that his American FAA certification, instrument rating, and UK IMC rating had all expired. Pilot error was deemed the most probable cause. The crash ended Embassy Hill, which shut down before the 1976 season.
Hill's record of 176 Formula One starts stood for over a decade until equalled by Jacques Laffite. He was inducted into the International Motorsports Hall of Fame in 1990. His son Damon Hill won the Formula One World Championship in 1996, making them the only father-and-son world champions in the sport's history. Graham Hill Bend at Brands Hatch is named in his honour, and streets in Silverstone village and Bourne, Lincolnshire — home to his former BRM team — carry his name. Beyond his accomplishments on the track, Hill was celebrated for his wit, his public personality, and his early advocacy for road safety, presenting a Thames Television series on advanced driving in 1974.