While contract details were not revealed, De Ligt's contract is reportedly worth 8 million euros per season, and could reach 12 million euros with bonuses.
There was even a brief comment from De Ligt as he declared he was "really happy to be here" before giving the waiting video camera the thumbs up.
Matthijs de Ligt is officially a Juventus player. - Ageing defence - The Turin-based club, now coached by former Chelsea mentor Maurizio Sarri, were keen to bring new blood into an ageing defence that features 34-year-old Giorgio Chiellini and Leonardo Bonucci, 32.
The Dutch prodigy helped lead Ajax to another Eredivisie title this past season, and they came within a whisper of the Champions League final, eliminating Juventus along the way.
De Ligt was confirmed as a Juventus player on Thursday morning after passing a medical.
He took over the captain's armband at Ajax in March 2018, making him the club's youngest ever captain.
It appeared at various points in the summer each side was close to signing him but it is the Italian giants who win this rat race.
At 19 years of age, Matthijs de Ligt has emerged as one of the best central defenders of the moment, with a promising future.