Coulthard came from a motorsport family — his grandfather competed in the Monte Carlo Rally and his father was Scottish National Kart Champion. He began karting at age eleven, winning the Scottish Junior Kart Championship and the Cumbria Kart Racing Club Championship before transitioning to car racing in 1989.
He progressed through British Formula Ford and the British Formula 3 Championship, where he won the Macau Grand Prix and the Masters of Formula Three in 1991 while driving for Paul Stewart Racing. He moved to International Formula 3000 for 1992 and 1993, finishing third in the series in his second season.
Coulthard was the first recipient of the McLaren/Autosport Young Driver of the Year award, which granted him a test in a McLaren Formula One car.
Coulthard had been serving as Williams' test driver when Ayrton Senna was killed at the 1994 San Marino Grand Prix. He stepped in as a race driver for the remainder of the season, scoring his first points with fifth place in Canada and achieving a podium with second place in Portugal. He finished eighth in the championship.
In 1995, partnering Damon Hill at Williams, Coulthard won his first Grand Prix at the Portuguese Grand Prix at Estoril, taking pole position and leading most of the race. He finished the season third in the Drivers' Championship. A contract dispute at the end of 1994 had temporarily threatened to send him to McLaren early, but a ruling by Formula One's Contract Recognition Board kept him at Williams for 1995.
Coulthard joined McLaren for 1996, partnering Mika Häkkinen in what became one of the sport's most celebrated driver pairings. His early seasons with the team were marked by occasional victories but also reliability problems. He won in Australia in 1997 and at the Italian Grand Prix that same year, finishing third in the championship.
In 1998, Coulthard helped McLaren win the Constructors' Championship. A controversial incident at the Belgian Grand Prix, where he collided with Michael Schumacher while being lapped, led to a heated confrontation in the pit lane; Coulthard later acknowledged the crash was his fault. He finished third in the championship.
The 1999 and 2000 seasons brought further wins, including victories at the British and Belgian Grands Prix in 1999 and at Monaco and France in 2000. His victory at Magny-Cours in 2000 — which he described as the most memorable of his career — was McLaren's only win at that circuit.
In 2001, Coulthard achieved the best championship result of his career, finishing second to Michael Schumacher by 58 points after wins in Brazil and Austria. His final victory with McLaren came in Monaco in 2002. He was dropped by the team at the end of 2004 in favour of Juan Pablo Montoya, having scored 13 wins, 12 pole positions and 62 podiums for the Woking squad.
He was awarded the Hawthorn Memorial Trophy — given to the most successful British or Commonwealth driver in Formula One — four consecutive times between 1998 and 2003.
Coulthard joined the newly formed Red Bull Racing team in 2005. The car was rarely competitive for wins, but he gave the team its first podium finish — third place at Monaco — in 2006. He retired from Formula One at the end of 2008, announcing his decision before the British Grand Prix. His final racing years with Red Bull yielded a further podium in Canada in 2008. His career total stands at 13 wins, 12 pole positions, 18 fastest laps, and 62 podium finishes across 246 starts.
Coulthard returned to racing in 2010, joining Mücke Motorsport in the Deutsche Tourenwagen Masters. He competed in the series for three seasons, scoring modest points totals before announcing his retirement from racing ahead of the final round at Hockenheim in 2012.
After his F1 retirement, Coulthard joined the BBC as a co-commentator and pundit alongside Martin Brundle, and later transitioned to Channel 4 in 2016 when that broadcaster took over British terrestrial television coverage of Formula One. He has also worked for the Nordic streaming service Viaplay since 2022, appearing alongside Mika Häkkinen and Tom Kristensen.
Coulthard has been a regular competitor in the Race of Champions, finishing runner-up in the Drivers' Cup in 2008 and winning the competition outright in 2014 and 2018.
Coulthard was appointed MBE in the 2010 Birthday Honours for services to motorsport and was elected president of the British Racing Drivers' Club in 2019. His 13 Formula One victories make him one of the most successful British drivers in the history of the championship, and his nine years at McLaren alongside Häkkinen represent one of the most productive driver partnerships of the late-1990s era.