“We have been watching him for a long time now and he is a player who will add quality to our squad.”
Xhaka, who has 40 caps, was once described as a young Bastian Schweinsteiger by legendary German coach Ottmar Hitzfeld.
He said: “It’s an honour. But I don’t know if I’m a Schweinsteiger. I am Granit Xhaka. I am very happy to be here. It’s a dream come true.
“Ever since I was young and I first saw a Premier League game, it’s been a big dream for me to play here. Now I’m here and I’m very happy.
“I’m very proud to be joining Arsenal. I cannot wait to move to London, represent this special club and play in the Premier League.
“I will give everything to help Arsenal win trophies and make the fans happy.”