The Ajax captain will play for the Serie A champions next term after Juve saw off competition from clubs including Paris Saint-Germain, Barcelona and Manchester United.
De Ligt's star rose last term with Ajax reaching the semi-finals of the UEFA Champions League, as well as claiming a domestic double under coach Erik ten Hag.
But he now faces justifying a fee of €75million, potentially rising to €85.5m, that makes him the most expensive under-20 defender of all time. Here's a look at the 10 most expensive teenage transfers and how they fared.
Kylian Mbappe: Monaco to Paris Saint-Germain - €180m
Likely to remain the world's most expensive teenage signing for some time, Kylian Mbappe is already well on the way to justifying the €180m outlay PSG made to prise him away from Monaco two years ago.
Mbappe had fired Monaco to a shock Ligue 1 title triumph before departing and his goals have continued to flow in the French capital with 33 in just 29 Ligue 1 games last season.
Still just 20, Mbappe has arguably eclipsed team-mate Neymar already, while he has won a World Cup with France. Pele has acknowledged comparisons with the forward, who looks a certain Ballon d'Or winner in the near future.
It would take a world-record fee to buy Mbappe, but he has hinted he could be open to leaving PSG.
Joao Felix: Benfica to Atletico Madrid - €126m
Potentially rivalling Mbappe for top individual honours in the years to come could be Joao Felix, who shoulders the burden of replacing Antoine Griezmann at Atletico Madrid, assuming the forward forces through his desired move away from the Wanda Metropolitano.
Joao Felix hit 20 goals in all competitions for Benfica last term, three of those strikes coming in the Europa League, to announce himself among the world's top talents.
It remains to be seen whether he is ready for the step up, with Atletico gambling €126m that the 19-year-old is a star of the future.
Matthijs de Ligt: Ajax to Juventus - €85.5m
Barcelona were linked with De Ligt, having already sealed a deal for club and country team-mate Frenkie de Jong, but the Ajax captain has instead opted for Serie A. There, he will work under the new Juve head coach Maurizio Sarri with European success demanded after the arrival of Cristiano Ronaldo failed to deliver the prized Champions League.
Domestic dominance is virtually assured, but De Ligt will have to show he can slot straight into one of the planet's tightest defences. A high-profile mistake against England in the Nations League semi-finals showed De Ligt is not yet the complete package, but Italy could be the ideal finishing school.
Anthony Martial: Monaco to Manchester United - €60m
Eyebrows were raised when United parted with €60m for Martial in 2015, with one British newspaper describing the deal as a "waste of money" in a back-page splash. Martial has not quite proved that assessment wrong, although he scored 10 goals in 27 Premier League appearances last term.
At 23 he has further development to come and the departure of Jose Mourinho, whose lack of faith in the France forward appeared clear, might well help him make a jump to the next level under successor Ole Gunnar Solskjaer.
Rodrygo Goes: Santos to Real Madrid - €45m
Real Madrid have been signing young talent in recent seasons in a departure from their Galactico-focused days, although the signing of Eden Hazard and a potential deal for Paul Pogba may change things.
Rodrygo Goes will link up with Zinedine Zidane's squad for 2019-2020 having remained on loan with Santos after completing a transfer to the LaLiga giants. The 18-year-old is full of promise and Madrid will hope he can be their Neymar.
Vinicius Junior: Flamengo to Real Madrid - €45m
Rodrygo is following in the footsteps of fellow Brazilian Vinicius Junior, who was a rare shining light for Madrid last term, scoring two LaLiga goals.
It remains to be seen where Zidane sees Rodrygo and Vinicius fitting in, especially as Hazard seems certain to take up one of the attacking positions and Luka Jovic has also arrived from Eintracht Frankfurt to compete for a striking berth.
Fitting everyone in seems set to be a challenge, but Vinicius could be Madrid's future along with Rodrygo.
Luke Shaw: Southampton to Manchester United - €37.5m
Like Martial, Luke Shaw is another player who seems to have laboured under a large price tag at times – which perhaps should be a warning sign for new arrival Aaron Wan-Bissaka after the 21-year-old joined from Crystal Palace.
Shaw also had a fractious relationship with Mourinho but made the United left-back spot his own with 29 Premier League starts in 2018-19.
The 23-year-old will hope to make further progress this term, but did not make the cut for Gareth Southgate's England squad for the Nations League Finals, with Ben Chilwell and Danny Rose preferred.
Wayne Rooney: Everton to Manchester United - €37m
Wayne Rooney certainly repaid his fee – he was British football's most expensive teenager – becoming United's all-time leading goalscorer and winning five Premier League titles at the club, as well as the 2007-2008 UEFA Champions League.
Rooney will go down as a United great despite affairs such as agitating for a move and falling out with Alex Ferguson. Rooney dropped out of favour in the latter years of his time at Old Trafford and was also sidelined for England, with a return to boyhood club Everton failing to spark. But joining MLS strugglers DC United has been a clever move and Rooney, now 33, is inspiring their rise.
Renato Sanches: Benfica to Bayern Munich - €35m
Bayern thought it was signing a player who would become one of the era's dominant midfielders when it snapped up Renato Sanches from Benfica, but the transfer has not worked out at all. Bayern bought Sanches before he won Euro 2016 with Portugal but, three years later, that remains the highlight of his career.
Sanches flopped in a loan spell with Swansea City in the Premier League and seems surplus to requirements at Bayern. The 21-year-old desperately needs to kickstart his career with a move away and has been linked with Turkish giant Fenerbahce.
Gabriel Jesus: Palmeiras to Manchester City - €32m
Handed City's number nine shirt ahead of the 2019-2020 season, Gabriel Jesus seems set for a defining campaign. At times after his arrival from Palmeiras the Brazil striker – who just helped his side win the Copa America on home soil – seemed to be preferred to Sergio Aguero by City boss Pep Guardiola, but the tables were turned last term as the Argentina attacker finally won his manager's total faith.
Jesus was restricted to just eight Premier League starts in 2018-19 but still scored seven times and he was picked over Aguero for the FA Cup final demolition of Watford, in which he scored a brace.