Levi Colwill has joined on a season-long loan from Chelsea.
The England under-19 defender had a successful spell with Huddersfield Town last season and will now spend the new Premier League campaign with Albion.
Head coach Graham Potter said, “Levi has enormous potential and has already shown his ability last season in the Championship and with England at various age group levels up to under-21s.
“I am really looking forward to working with him on the training pitch, and in matches over the course of the season.
“He plays mostly at centre-back, but has also played on the left as a full-back, and he is a player who is comfortable on the ball.”
Levi has been with Chelsea since joining their under-9s squad over a decade ago and has come through the club’s academy.
Last June he signed a new four-year Chelsea contract before his move to Huddersfield.
He made 29 league appearances for the Terriers, helping them to a third-place finish in the Championship and to gain a place in an ultimately unsuccessful Championship Play-Off Final.
Levi, who will be ineligible for the two games against parent club Chelsea this season, has also captained England at under-19 level.