The 24-year-old has signed a four-year contract and joins the Spanish fee for a fee believed to be around €7million.
“I wanted to sign for one of the best club’s in Europe,” he told their official website.
“I’m happy to be a part of this club.”
Alderweireld has also been linked with the likes of Bayer Leverkusen and Liverpool this summer.
What is your opinion? Feel free to discuss the article under. You have to comment by using your Facebook profile. Be fair and have respect for other people and opinions!
Liverpool have unveiled their new home kit for next season, sticking with the hugely popular retro styling of the current shirt.
The reputation of the Premier League means it is the most popular and one of the most watched leagues in the world.