Alfie Mawson has completed a move to Swansea City from Barnsley, becoming the sixth signing of the transfer window for the Premier League side.
An undisclosed fee had already been agreed with the Championship club and Mawson signed a four-year deal at Swansea on Tuesday.
Mawson, who has scored twice for Barnsley this season, helped the club to win last season's Football League Trophy and seal promotion to the second tier.
The 22-year-old follows Borja Baston, Fernando Llorente, Leroy Fer, Mike van der Hoorn and Mark Birighitti in joining Francesco Guidolin's side.
Mawson told Swansea's official website: "Coming here is a fantastic opportunity for me. Two-and-a-half or three years ago I was playing in the Conference [National League].
"It's a big leap, a big step up for me, even from the Championship, but it's an opportunity I am going to try to grab with both hands.
"I think having confidence is massive. I genuinely feel I can make the step up, although I know that only time will tell.
"I am sure I will learn things about myself and my game, but I am here to improve as a player and a person.
"I am really looking forward to the opportunity. It's great to have been purchased by such a big club and a club I feel is very suited to me. I am just looking forward to getting going now."
