Manager Eddie Howe warmly welcomed the arrival of the Abdelhak Nouri Trophy winner, who follows in the footsteps of big names like Christian Eriksen and Rafael van der Vaart as the Ajax academy's brightest talent.
Howe stated: "We’re delighted to welcome Sean to Newcastle United - he’s a top young prospect that has already tasted Champions League and top-flight Dutch football. We see real potential in Sean and believe he has the characteristics to become a valuable player for us for years to come. That’s something we’re really excited by and look forward to working with him and helping him achieve his ambitions.
"Sean is an exciting addition to our squad. He’s had an excellent upbringing at Ajax, who have an outstanding track record of producing young players."
Meanwhile, the Amsterdam outfit also released an official statement to bid farewell to the player, who holds the record as Ajax's youngest-ever assist maker in the Champions League. The Johan Cruijff ArenA-based club added: "Ajax has thanked Steur for his years in Amsterdam and wished him much success with this next step in his career in the English Premier League."