The Austrian had been battling health problems since the middle of last year, including a lung transplant in August that required a two-month hospital stay.
He was then hospitalized again for a short period in early 2019 after contracting a flu infection. There have been reports from the Austrian press in recent days that he had been receiving kidney dialysis in Switzerland.
Unfortunately, now it has been confirmed that he has succumbed to his ill health, dying on Monday surrounded by relatives.
"With deep sadness, we announce that our beloved Niki pbaded away peacefully with his family on Monday," his family said in a statement issued to the Austrian media.
"His unique achievements as an athlete and entrepreneur are and will be unforgettable, his tireless enthusiasm for action, his simplicity and his courage remain."
"A role model and a point of reference for all of us, was a loving and affectionate husband, father and grandfather, far from the public, and we will miss him."
Lauda was a giant of the Formula 1 paddock for more than four decades. He debuted in 1971, won his first race in 1974 after joining Ferrari and then won a first title in 1975.
The following season was lucky to survive a fierce crash at the Nürburgring, which left him very burned. Note that only two races were lost, making one of the most remarkable comebacks in the history of the sport, and only missed the championship by a single point against James Hunt of McLaren.
The second title for Ferrari came in 1977, before Lauda moved to Brabham for the 1978 season. His season there lasted less than two seasons, Lauda retired from Formula 1 halfway through the practice for the Canadian Grand Prix of 1979.
Then he focused on his incipient air charter business in Austria until 1982, when he made his return to Formula 1 with McLaren. That relationship produced a third World Championship two seasons later, when he beat teammate Alain Prost by only half a point.
After his second retirement in 1985, in the 1990s, Ferrari badumed the position of consulting manager, followed by the work of team manager at Jaguar, which he accepted in 2001, but which lasted only until 2002.
In 2012, he became the non-executive president of the Mercedes F1 team, and was a key figure in the squad winning multiple titles until his illness last year.