Kalvin Phillips has completed his transfer from Leeds United to Manchester City.
The midfielder joins the Premier League champions for a fee thought to be in the region of £45million, with potential add-ons.
He has signed a six-year contract.
Phillips said: "City have again proved to be the best team in the country with an amazing squad and a manager in Pep Guardiola who is rightly considered to be the finest in the world.
"To be able to play under Pep and learn from him and his coaching staff as well as be part of a such a fantastic squad is a prospect that I am incredibly excited about."
The 26-year-old midfielder made 234 appearances over the course of eight seasons for Leeds, scoring 14 goals and assisting 14.
City's director of football Txiki Begiristain said: "Kalvin is a player that we have long admired, and at both domestic and international level, he has proved his fantastic ability and quality over the past few seasons.
"His reading of the game, alongside his passing ability, energy and drive make him a formidable talent and he is a player who has a fantastic will to win.
"We feel he will be a superb addition to our squad and that he will complement our game perfectly."
Having worn the number 23 shirt at Leeds, Phillips will play in the number 4 jersey at City, last worn by club legend Vincent Kompany.
"It was a number that was presented to me, and I thought because at Leeds I had 23, which is one of my favourite numbers, I felt like because it's a new start. I wanted a different number and to try and build a legacy on that number," said Phillips.
Phillips joined Leeds at the age of 14 and progressed through the Academy, before going on to make his first team debut against Wolverhampton Wanderers in April 2015.
In a statement, the Elland Road club said: "No words can thank Kalvin enough for his efforts whilst at the club and we wish him nothing but success in the future.
"Kalvin inspired so many people in the city, not only for what he did on the pitch, but also for the work he did in the local community.
"He will always be a champion in Leeds, remembered for playing his part in getting the club back to where it belongs and will always be welcome at Elland Road."