Tomas Kalas joined Bristol City on a season-long loan from Chelsea.
Kalas, 25, spent last season on loan at Fulham, playing a key role as they won promotion to the Premier League via the play-offs.
The Czech centre-back is the second player to join City on loan from Chelsea this summer.
He joins Jay Dasilva, who also recently signed for the Robins on a season-long deal.
“The experience Tomas brings to this football club will be invaluable and I am really looking forward to working with him,” City manager Lee Johnson told the Championship club’s website.
“He has already proven himself at Championship level and I have no doubts that he can help us in our bid to reach new heights.”