The Toon have completed the signing of Switzerland defender Schar after activating his £3million release clause.
The Deportivo La Coruna centre-back underwent his medical on Tyneside on Thursday and has put pen to paper on an initial three-year deal.
His arrival is a timely one for manager Rafa Benitez, who has been frustrated by the lack of movement in the transfer market with Ki Sung-yueng the only addition to the squad which finished 10th last season.
The 26-year-old said: “I'm really happy to be here. The club is a really big club for me. It has a big name, and it is a brilliant chance for me.
“I'm not like a typical defender. I, of course, defend, but I'm quite good with the ball – I like to play, I want to build up the game from behind, and I think that is a strength of mine. I have also scored some headers – that could also be a strength and hopefully I can use it here.
“I hope to start training with the team soon, and I'm looking forward to everything that's coming. At the moment, I just want to get started."