Häkkinen was born in Helsingin maalaiskunta (now Vantaa), Finland on 28 September 1968 to Harri, a shortwave radio operator and a part-time taxi driver, and Aila Häkkinen, who worked as a secretary. Häkkinen grew up with one sister, Nina, who ran a fan site for her brother until its closure in 1998. As a child, Häkkinen lived in the same street as Mika Salo with the two later becoming friends. As a child, Häkkinen played ice hockey and football.

When Häkkinen was five years old, his parents rented a go-kart for him to take to a track near their home. On his first lap, Häkkinen was involved in an accident but he escaped unhurt. Despite this crash, Häkkinen wished to continue racing and after persistently annoying his parents, the young Finn got his wish fulfilled. His father bought Häkkinen his first go-kart, one that Henri Toivonen had previously competed with. He later won his first karting race in 1975 at the Keimola Motor Stadium where he raced in the regional karting championships in 1978 and 1979, winning the Keimola Club Championship in both years. Häkkinen found further success in 1980 when he won the Swedish Lapland Cup and finished fourth in the 85cc class of the Lapland Karting Championship. Around this time, Häkkinen also drove a Volkswagen Beetle on the frozen lakes of Finland with friend Mika Sohlberg.

In 1981, Häkkinen driving for the Blue Rose karting team won his first major karting title, the 85cc class of the Finnish Karting Championship. The following year, he finished the 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, Jaane Nyman and Marko Mankonen, with the line-up taking the championship.

For 1984, Häkkinen won the 100cc Formula Nordic title and later participated in the World Kart Championship race held in Liedolsheim. Häkkinen took his second consecutive 100cc Formula Nordic Championship in 1985 ahead of Jukka Savolainen. He later took part in the Nordic Championship A-Class in that same year, finishing runner-up to Tom Kristensen. Häkkinen went to Parma to participate in the World Kart Championship where he retired before the event’s final heat due to a mechanical problem. In 1986, he reached his third consecutive Formula Nordic 100cc title and also took part in karting events across Europe. To further fund his career, Häkkinen got a job with a friend repairing bicycles.

In 1987, Häkkinen made the transition from karting to car racing when he purchased a 1986 Reynard Formula Ford 1600 from fellow countryman JJ Lehto. 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. Häkkinen also entered two races of the EDFA 1600 Championship and raced in the Formula Ford Festival held at Brands Hatch, where he finished in seventh position. In 1988, Häkkinen entered the EFDA Formula GM Lotus Euroseries with the Dragon team, where he secured four victories and finished the runner-up in the championship, behind Allan McNish. He later entered the Opel-Lotus EDFA Euroseries, taking four victories and became Champion with 126 points, ahead of nearest rival Henrik Larsen.

Going into 1989, Häkkinen moved from the Euroseries into the British Formula 3 Championship driving a Reynard 893 chassis for Dragon. He only secured seventh position in the championship, scoring 18 points. 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. He also raced in the tenth round of the French Formula 3 championship at Le Mans-Bugatti on September 24 and finished third behind Éric Hélary and Laurent Daumet.

In 1990, Häkkinen applied to become a member of the “Marlboro World Championship Team” through what was akin to a fully sponsored racing driver academy. Its members were short-listed for testing by a judging panel including McLaren F1 team boss Ron Dennis (whose team was sponsored by Marlboro), F1 World Champion James Hunt, and Formula 3000 team bosses, Mike Earle and Hugues de Chaunac. In an April 2015 interview, Earle recounted that Häkkinen’s application was the last application he reviewed at the end of a particularly long day ended at 7pm, despite protests by fellow reviewer James Hunt who had already made plans to head to a pub for a beer. Häkkinen aced his test and went on to secure Marlboro’s sponsorship. 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 countryman Salo. In November, Häkkinen entered the Macau Grand Prix where he drove to pole position and won the first heat of the event. He retired from the second heat due to a last-lap collision with German Formula Three driver and future F1 rival Michael Schumacher, who was classified as the overall winner.

For 1993, Häkkinen joined McLaren, originally as a race driver, although he became the team’s official test driver when CART World Series driver Michael Andretti was hired by the team. Apart from regular testing duties, Häkkinen entered two Porsche Supercup races, held as a support race for the Monaco Grand Prix, where he started at pole position and took victory in both races. He was promoted to a Formula One race seat after the Italian Grand Prix, when Andretti left Formula One. Häkkinen entered the Portuguese Grand Prix where he out-qualified regular driver Ayrton Senna. During the race, he retired due to collision with a concrete wall. At the next race held in Japan, Häkkinen claimed the first podium of his career with a third-place finish, and ended the season when his McLaren car suffered a brake pipe failure in Australia. Häkkinen concluded the season with 15th in the Drivers’ Championship, scoring 4 points. In December, McLaren confirmed that Häkkinen would remain with the team on a three-year contract from the 1994 season onwards.

During 1993, Häkkinen, along with Senna, tested the Lamborghini V12 engine in a modified version of the McLaren MP4/8 race car dubbed the “MP4/8B” at both Estoril and Silverstone. Both drivers were impressed with the engine, with Häkkinen reportedly lapping Silverstone some 1.4 seconds faster in the MP4/8B with its V12 engine than he had with the team’s race car fitted with the Ford V8.

The 1996 season was the first in which Häkkinen was the more experienced driver in his team and was partnered by David Coulthard. Häkkinen was confident going into the season and set himself a target of winning races. To ensure his fitness, Häkkinen spent time training in Bali and in February, McLaren conducted a secret test at the Paul Ricard Circuit. In the event that Häkkinen was not prepared, McLaren had Magnussen to replace him should the need arise. The season started well for Häkkinen: He earned consecutive points-scoring positions in the opening two rounds, before he suffered his first retirement of the season in Argentina as his car developed a throttle problem. He later finished the next two races, albeit outside of the points scoring positions, before returning consecutive finishes inside of the points in the following four races.

At the season finale held in Australia, Häkkinen’s car suffered a tyre failure during the event’s first qualifying session on Friday, which resulted in his car becoming airborne and crashing sideways into the crash barrier on the outside of Brewery corner, the fastest corner of the Adelaide Street Circuit, at an estimated speed of 120 mph. The session was suspended with Häkkinen being critically injured due to sustaining a skull fracture, internal bleeding and a blockage of his airway. His life was saved by the efforts of the trackside medical team which included doctors Jereme Lockings and Steve Lewis from the Royal Adelaide Hospital, one of whom performed an emergency cricothyroidotomy at the trackside. Häkkinen was immediately transported by ambulance to the nearby Royal Adelaide Hospital which was luckily located only about half a kilometre from the circuit. There he remained in a critical condition under care of the Trauma Service, the Neurosurgical Unit, and the Intensive Care Unit and remained in the hospital for approximately two months. He eventually made a remarkable recovery. 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.

Häkkinen married Erja Honkanen, a former TV journalist, in 1998. The couple have one son and one daughter. The couple applied for divorce in 2008. Häkkinen also has two daughters and a son by his Czech girlfriend Markéta Remešová.

Häkkinen followed this up by taking consecutive podiums in the next two rounds—third in France and second in Britain. He managed further consecutive victories in the next two rounds, and followed this up with a sixth-place finish in Hungary. In August, it was announced that Häkkinen and Coulthard would be retained for 1999. Häkkinen retired from the following race held in Belgium when Ferrari driver Michael Schumacher collided with the Finn and was also hit by Sauber driver Johnny Herbert. He later managed a fourth position in Italy despite suffering from brake problems resulting from a spin. Häkkinen finished the season by taking victory in the final two rounds at the Luxembourg Grand Prix and the Japanese Grand Prix, which ensured he took enough points to clinch the 1998 World Championship, with 100 points, ahead of nearest rival Schumacher. Häkkinen was awarded the Autosport International Racing Driver Award for 1998. He was also named the Finnish Sports Personality of the Year by journalists. The Finnish Post Office issued stamps to commemorate Häkkinen’s World Championship in January 1999.

For 2000, Häkkinen set himself new limits along with physical and psychological preparations for the upcoming season. He also believed that he along with Schumacher and Coulthard would be the key drivers of 2000. He endured a bad start: At the opening round in Australia, both McLaren cars retired with engine failure after completing less than half of the race distance; and in the following race in Brazil, Häkkinen was forced into retirement when his car’s oil pressure became problematic. However, this marked a turning point as Häkkinen took consecutive second-place finishes in the next two rounds, and later reached his first victory of the season in Spain.

For 2001, Häkkinen pledged to make a challenge for the World Championship, citing inspiration from the birth of his son Hugo. He also added that he was under less pressure to compete, saying that results over the previous year increased his desire to win. The season started badly for Häkkinen: He was forced into retirement in the opening round held in Australia due to a failure with his car’s suspension resulting in his car spinning violently into a tyre barrier. The McLaren cars were off the pace in Malaysia, with Häkkinen managing to end at the 6th place. He retired from the following race in Brazil when his car stalled on the starting grid, Further points came at the San Marino Grand Prix. 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.

Before the Italian Grand Prix, Häkkinen announced that he would be on a sabbatical for the 2002 season, citing the reason to spend more time with his family. His seat was taken by fellow countryman Kimi Räikkönen in 2002. Häkkinen later stated that fear after crashes during practice for the 1995 Australian Grand Prix and the 2001 Australian Grand Prix as well as a loss of a desire to compete for race victories were factors. He was forced into another retirement during the race due to a gearbox issue. He raced to his final victory of his career in the United States despite incurring a grid penalty, and ended the season with a fourth-place finish in Japan. Häkkinen finished the season fifth in the Drivers’ Championship, with 37 points.

In July 2002, nine months into his sabbatical, Häkkinen announced that he would be retiring from Formula One. It was later revealed that Häkkinen approached McLaren team principal Ron Dennis during the 2001 Monaco Grand Prix and agreed a sabbatical, then returned to Monaco the following year to discuss and agree full-time retirement with Dennis. In October, Häkkinen made his first appearance as a commentator for pay-for-view channel Canal Digital at the United States Grand Prix.

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. He also stated that he would not move full-time into rallying and learn about driver control, although he later stated he would enter more rally events if he finished within the top two. Making his debut in the Arctic Rally, Häkkinen was delayed by four minutes as his team changed a tyre and eventually finished 30th. He once again entered the event in 2004 driving a Toyota Corolla with co-driver Risto Pietiläinen and finished seventh.

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. In May, McLaren team principal Ron Dennis dismissed the rumors, stating that Häkkinen was not prepared for a comeback. Häkkinen held talks with BAR and Williams and later decided against returning to Formula One saying in 2005: “It’s impossible to think that I would race a Formula One car again because as time passes my reactions become slower and my eyesight gets worse – that’s life.”

On 6 November 2004, it was announced that Häkkinen would make his debut in the Deutsche Tourenwagen Masters (DTM) series for the HWA Team in the 2005 season. He was partnered by Gary Paffett, Jean Alesi and Bernd Schneider. Häkkinen had previous experience of driving touring cars in July 2001 at the Brno Circuit alongside Schneider. In January, Häkkinen once again participated in the Arctic Rally driving a Toyota Corolla with co-driver Risto Pietiläinen. Häkkinen retired when he slid off the road on the eleventh stage.

On 15 November 2005, it was announced that Häkkinen would remain with HWA for the 2006 season, and was partnered by Alesi, Spengler and Jamie Green. For the upcoming season, Häkkinen set his target of winning the championship, although he believed the competition from Audi would make the title challenge difficult. Outside of DTM, Häkkinen participated in his fourth Arctic Rally, driving a Mitsubishi Lancer Evolution VII with co-driver Risto Pietiläinen. He finished 36th overall.

Häkkinen joined Johnnie Walker as their Global Responsible Drinking Ambassador in September 2006, campaigning for the message of responsible drinking. He also led the organisation’s Join the Pact campaign to spread consumer commitments for the prevention of drunk driving. He is also brand ambassador for Mercedes-Benz and UBS. In 2016, he became an official brand ambassador for Nokian Tyres.

On 28 January 2007, it was announced that Häkkinen would remain in DTM for the 2007 season for HWA, and was partnered by Spengler, Green and Schneidler. Häkkinen stated that during 2006, his team’s potential was not realised and aimed during 2007 to improve on his results. He started the season by earning consecutive finishes in the first two races, albeit outside of the points scoring positions. At the third race of the season held at EuroSpeedway Lausitz, Häkkinen won his first race of the season although only half points were awarded due to errors made by race organisers, resulting in the official race result remaining provisional. He held pole for the following race at Brands Hatch where he finished in fourth position, and followed the result with a ninth-place finish at the Norisring.

Häkkinen announced his retirement from competitive motorsport in November 2007. He was quoted as saying that the decision “was not an easy one”, but added that “racing is still in my blood and this decision does not mean that this will prevent me from racing for pleasure”.

In November 2008, it was announced that Häkkinen would start a new career in driver management and would work alongside Didier Coton in his firm Aces Associate Group. 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. Häkkinen made his debut in sports cars when Team AMG China entered a Mercedes-Benz SLS AMG in November 2011 to participate in the Intercontinental Le Mans Cup at the 6 Hours of Zhuhai race alongside Lance David Arnold and Cheng Congfu. During the event, the team retired after completing two hours. 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. Häkkinen drove to victory in the first race after starting from sixth position. The victory resulted in a 15-second handicap during his mandatory pitstop for his second race and finished in fourth position.

Häkkinen has resided in Monaco since 1991. He also owns properties in France and Finland. On 18 May 2008, his newly completed mansion in France was burned down after a light in one of his trophy cabinets short circuited. No injuries were reported, although Häkkinen’s collection of Formula One trophies was destroyed. Outside motorsport, Häkkinen enjoys skiing, swimming, tennis, scuba diving and jet ski. His favourite music acts are Phil Collins, Michael Jackson, Frank Sinatra and J. Karjalainen.

In November, Häkkinen tested a McLaren MP4-21 for one day at the Circuit de Catalunya where he completed 79 laps. To prepare himself, Häkkinen spent time at the McLaren Technology Centre to acquaint himself with Formula One’s revised regulations. In a 2017 retrospective interview Häkkinen revealed that he had been in advanced talks with McLaren for a return in the 2007 season. He had however been frustrated by problems with McLaren’s car in the test, which had reminded him of the reasons why he had taken the sabbatical in the first place, so the plans had collapsed.

On 16 March 2017, McLaren announced that Häkkinen has rejoined the team as partner ambassador.

On 9 April 2019, it was announced that Häkkinen would race in Suzuka 10 Hours which is the 4th round of the 2019 Intercontinental GT Challenge driving a McLaren 720S GT3 alongside two-time Super Formula champion Hiroaki Ishiura and Japanese Formula 3 racer Katsuaki Kubota on August 23–25, with Planex Smacam Racing.