The versatile 23-year-old, who usually operates in central midfield, has put pen to paper on a five-year contract with Alan Pardew's side and will wear the No.8 shirt this season
The Netherlands international operates primarily as a central mdifielder but can also fill in at full-back and has signed a five-year contract with the Magpies.
Newcastle manager Alan Pardew expressed his delight at the completion of the deal and hoped that Anita had his best years as a player ahead of him.
"We are delighted to secure the services of Vurnon," Pardew told the club's official website.
"He is an exceptionally talented footballer with great technical ability, which is exactly what I'm looking at in a player. And, at 23-years-old, we hope his best years are at Newcastle."
Anita played a key role in Ajax's Eredivisie title winning campaign last season, scoring two goals in 17 games, and is known for his work ethic and tireless attitude.
Pardew revealed that he will be ready for the season opener against Tottenham on Saturday as he has already completed a full pre-season.
"He has come through the Ajax youth system which is world renowned for bringing up players the right way, and I am sure he will fit seamlessly into the squad of players we have here," he continued.
"Vurnon has done his pre-season, and indeed already played one competitive game, so he's up to speed and ready to play when I need him."
During his time in Amsterdam, Anita won both the Eredivisie title and the Dutch Super Cup twice as well as lifting the Dutch Cup on three occasions, and is now ready for a new challenge.
"I won almost everything in Holland so the step was not difficult to make," Anita said upon his arrival on Tyneside. "Now I think we can also win trophies with Newcastle and it's time to do that.
"In the Premier League especially, every game is tough so it can help me also to grow in my football skills."
Anita added that he had spoken with Pardew about the role he would play in the Magpies team, admitting that he preferred a midfield berth.
"I talked to the manager and the coach and they know that I want to play in a defensive midfield place and that's why they brought me here," he revealed.
"But I can play at left-back or right-back, so that's also no problem."
Fellow Dutchman Tim Krul also expressed his delight at Anita's capture and his hope that more players will arrive at Sports Direct Arena this summer.
He tweeted: "Over the moon with the signing of my friend Vurnon Anita he's going to be a top player for us. Hopefully couple more signings to come."