"Wayne's a player I know I played alongside him at Southampton and I saw him come through the ranks," City boss Mark Hughes said of his first signing of the January transfer window.
"He was an outstanding young player and he's progressed year on year in his career.
"He's a successful player. He's an England international and has just played for one of the top four sides in the country.
"He's of the right quality and he's the type of player we need to attract.
"We need good players that understand this league and we'll look to carry on in that way and add more if we can."