A member of the Marlboro driver academy, Häkkinen signed for Lotus in 1991, making his Formula One debut at the United States Grand Prix.

Amidst a fierce title battle with Michael Schumacher in 1998, Häkkinen won his first championship at the final race of the season, becoming the second World Drivers' Champion from Finland.

Häkkinen retired at the conclusion of the 2001 season—taking his final victory at the United States Grand Prix—having achieved 20 race wins, 26 pole positions, 25 fastest laps and 51 podiums in Formula One.

The following year, he finished runner-up in the 85cc class of the Formula Mini series and later won the Ronnie Peterson Memorial event and the Salpauselka Cup in Lahti.

Häkkinen moved to the Formula Nordic 100cc class for 1983, where he became the champion on his first attempt and also participated in the A Junior Team Races for Finland alongside Taru Rinne, Jaana Nyman and Marko Mankonen, with the line-up taking the championship.

In that year, he entered the Finnish, Swedish and Nordic Formula Ford Championships, winning each title on his first attempt and won nine races combined.

He later entered the Opel-Lotus EDFA Euroseries in the same year, taking four victories and became Champion with 126 points, ahead of nearest rival Henrik Larsen.

He was later invited to participate in the Cellnet Formula Three SuperPrix for West Surrey Racing as a guest driver where he secured pole position and the victory.

[9] He also raced in the tenth round of the French Formula 3 championship at Le Mans-Bugatti on 24 September and finished third behind Éric Hélary and Laurent Daumet.

[10] In an April 2015 interview, Earle recounted that Häkkinen's application was the last one that he reviewed at the end of a long day, despite protests by Hunt who had already made plans to head to a pub for a beer.

That same year, therefore, Häkkinen left Dragon and moved to the West Surrey Racing team and won the British Formula 3 series, by taking nine victories en route to the Championship, with 121 points, ahead of fellow Finn Salo.

[13][14] Before Canada, Bailey lost his seat at Lotus due to a lack of funding,[15] so Häkkinen was partnered by Johnny Herbert and Michael Bartels throughout the remainder of the season.

[20] At the next race held in Japan, Häkkinen claimed the first podium of his career with a third-place finish,[21] and ended the season when his McLaren car suffered a brake pipe failure in Australia.

[25][26] He later reached his first podium finish of the season at the San Marino Grand Prix, although he suffered a dip in form as he was forced into consecutive retirements in the next four races.

[27] Häkkinen returned for the Belgian Grand Prix, initially coming third but was later promoted to second after the disqualification of Benetton driver Michael Schumacher.

During pre-season testing, Häkkinen and teammate Mansell complained the car, the McLaren MP4/10, was not wide enough to fit in, resulting in their hands and elbows striking the sides of the cockpit.

[30] Häkkinen started off the season by finishing fourth in Brazil,[31] and later retired in Argentina due to a collision which punctured his left rear tyre that followed a spin.

This did not revive Häkkinen's fortunes as he did not finish in the points scoring positions, and later suffered consecutive retirements in the next four races,[12] but got second place at the Italian Grand Prix.

His life was saved by the efforts of the trackside medical team, including the President of the FIA Institute for Motor Sport Safety, Sid Watkins, and volunteer doctors Jerome Cockings and Steve Lewis,[36] from the Royal Adelaide Hospital.

[40] As an expression of thanks for the elite class medical attention he received, Häkkinen donated a substantial undisclosed sum of money to help build a much-needed helipad for The Royal Adelaide Hospital, and made a special trip to Australia for the official opening ceremony in March 1997.

[42] To ensure his fitness, Häkkinen spent time training in Bali and in February, McLaren conducted a secret test at the Paul Ricard Circuit.

[50] Häkkinen later took ninth position at the Spanish Grand Prix,[12] but later suffered three consecutive retirements in the next three races—a collision with Ferrari driver Eddie Irvine in Canada and engine failures in France and Britain.

[87] Häkkinen raced to his second consecutive victory in Belgium, which included a simultaneous pass on Schumacher and Ricardo Zonta in the Kemmel straight.

[97] At the Spanish Grand Prix, Häkkinen looked on course to win his first victory of the season, until the final lap of the race, when his car was hampered with a clutch failure and was classified ninth.

[111] In December 2002, it was announced that Häkkinen would be participating in the Finnish Rally Championship driving a Mitsubishi Lancer Evolution WRC2 with his co-driver Arto Kapanen.

[116][117] During 2004, rumors circulated that Häkkinen was making a possible return to Formula One to fill in the vacant Williams seat left by Juan Pablo Montoya.

[138] In November 2008, it was announced that Häkkinen would start a new career in driver management and would work alongside Didier Coton [fr] in his firm Aces Associate Group.

[139] Häkkinen contested his fifth Arctic Rally event in January 2009 driving a Mitsubishi Lancer Evolution IX alongside co-driver Ilkka Kivimaki and finished 19th overall.

[143] In October 2013, Häkkinen participated in the GT Asia series for the two races held at the Zhuhai International Circuit, driving a Mercedes-Benz SLS AMG 300 alongside co-driver Matthew Solomon.

[156] Newey said that Häkkinen's countryman, protege, and future McLaren driver Kimi Räikkönen had a similar approach to input on car development.