Räikkönen was born on 17 October 1979 in Espoo, Finland, and began kart racing at the age of ten. He won several national karting titles across Finland and Scandinavia through the 1990s, including the Nordic Championship in 1998. His preparation for car racing was thorough but brief: a second-place finish in a round of the European Formula Super A championship for PDB Racing in 1999 gave him early single-seater experience, and he simultaneously competed in the Formula Ford Euro Cup that same year.
In the winter of 1999, Räikkönen won the British Formula Renault winter series, taking the first four races of the championship consecutively. The performance level was exceptional for a driver of such limited car-racing experience. Manor Motorsport, one of the series' leading outfits, was sufficiently impressed to retain him for the main 2000 championship.
Räikkönen's 2000 season with Manor in the British Formula Renault Championship was the statistical centrepiece of his junior career. He won seven of ten events, combining the winter series results for a total of thirteen wins from twenty-three events across both campaigns — a 57 percent win rate that remains one of the highest sustained averages in British Formula Renault history. The combination of pace, tyre management, and racecraft he demonstrated on circuits across the United Kingdom was the direct trigger for Sauber's interest.
Peter Sauber tested Räikkönen at Mugello in September 2000, and on just the second day of testing Räikkönen lapped half a second faster than regular Sauber driver Pedro Diniz. Sauber conducted the evaluation quietly, internally referring to Räikkönen as "Eskimo" to avoid alerting rival teams. After further tests at Jerez and Barcelona, Sauber signed Räikkönen for the 2001 Formula One season. The decision was controversial: FIA president Max Mosley and other critics questioned whether a driver with only 23 car races to his name should receive a Formula One superlicence. The FIA granted the licence only after Sauber submitted a personal performance guarantee. The debate around his eligibility would later look misplaced; Räikkönen scored a championship point on his debut at the 2001 Australian Grand Prix, finished his rookie season with nine points, and went on to win the 2007 World Drivers' Championship with Ferrari.
The British Formula Renault chapter in Räikkönen's story is significant precisely because it was so short. Most future world champions spent two or three seasons in junior formulae before attracting top-team attention. Räikkönen required less than two full seasons of car racing to earn a Grand Prix seat, with the British Formula Renault results being the sole substantive evidence of his ability. The Räikkönen case also prompted wider discussion within the FIA about superlicence criteria, eventually contributing to the points-based superlicence system introduced in 2016 that now mandates a defined level of junior-category success before a driver can compete in Formula One.