He was born James Clark Jr. into a farming family in Kilmany, Scotland, the only son of five children.
Clark's Formula 1 career was with the Lotus team, for whom he drove from 1960 to 1968. Major success came in 1963 with the Lotus 25, with Clark driving, won seven out of the ten races, and won Lotus its first World Championship. In 1965 he again won the championship. That year he also won the Indianapolis 500. He had to miss the prestigious Monaco Grand Prix to compete in it, but made history by driving the first rear-engined car to win the race.
The following year Lotus were uncompetitive under new 3-litre engine rules. They started the season with a 2-litre Coventry-Climax engine, in the Lotus 33. Later in the season, the Lotus-BRM 43 used a very complicated BRM H16 engine (essentially two flat-eight engines joined together). Clark won just once, at Watkins Glen.
On April 7, 1968 during a Formula Two race at the Hockenheim, Germany circuit, Jim Clark was killed instantly when a rear tire failed at 175 mph and his car veered off the race course and crashed into some trees. His death was a huge blow to the team and to racing. He was the dominant driver in the dominant car, and remains inseparable from Lotus's early years. The 1968 world championship was won by Clark's team-mate, Graham Hill.
In his Formula 1 career, Clark won 25 races, and gained 33 pole positions.