Born in Espoo, Finland. He was a protégé of Finland's 1982 Formula One World Champion Keke Rosberg, who first suggested that Jyrki Järvilehto would abbreviate his name to the more manageable JJ Lehto. Like many racing drivers he began in karts, winning numerous events, before graduating to Rally Driving. A switch to single seaters saw him dominate the Scandinavian Formula Ford and win the coveted British Formula 3 title in 1988. The following year Lehto tested for Ferrari before making his Formula One debut for the Onyx team. Financial difficulties forced the small team to quit Formula One in the summer of 1990 leaving Lehto free to move to Dallara, where he remained until the end of the 1992 season, when Dallara also withdrew. During that time he collected his only podium finish in the 1991 San Marino Grand Prix. In 1993 Lehto signed for the new Sauber team who had moved into Formula One from Sports car racing. There he partnered Karl Wendlinger. Despite failing to repeat his 1991 podium result, Lehto scored a respectable 5 points before signing for the front-running Benetton team to partner Michael Schumacher in 1994. Sadly, when it appeared Lehto was finally to receive his break in Formula One, disaster struck. A testing accident at Silverstone shortly before the beginning of the season forced him to sit out the first two races. Lehto made his return at the ill-fated 1994 San Marino Grand Prix, in which Roland Ratzenberger and Ayrton Senna were killed. In that race, Lehto's Benetton stalled on the starting grid and was plowed into by Pedro Lamy's Lotus. Instead of stopping the race to clear the track of debris and then restarting the race (which was the normal procedure at the time), race officials decided to bring out the safety car to lead the cars around the track until the track was clear. Some people believe that the loss of tire temperature and pressure that results from such an extended period of low speed driving may have contributed to Ayrton Senna's fatal crash on lap 6. Benetton were fighting for the constructors title in 1994 and despite a sixth place finish in Canada Lehto lasted only four races before once more being replaced by Jos Verstappen, who the team felt was in better form at the time. Lehto made two more appearances for Benetton in the latter stages of the season, but by now, with his confidence terminally damaged, it was clear that Lehto's Formula One career was effectively over. Benetton replaced him with Briton Johnny Herbert. Lehto was then drafted in to the Sauber team for the final two events of the 1994 season, races which would be his last in Formula One. In the following years Lehto was successful in other categories of motor sport, including a win at Le Mans in 1995 and 2005. In 2001 Lehto joined Finnish television as an expert race commentator. In 2005 Lehto joined Marco Werner and Tom Kristensen as a three man team, running an Audi R8 LMP to victory.