Signing on loan until the end of the 2021-22 season, Callum Doyle is coming over to Wearside from Premier League champions Manchester City.
The 17-year-old has featured twice in the EFL Trophy and made a further 14 appearances for the club’s title-winning Under-18s, contributing three goals and three assists across City’s respective development sides.
Head coach Lee Johnson said: “We are grateful to Man City for believing in us as a club to be able to help develop somebody like Callum.
"He is a very talented player, but obviously he is still very young, so the expectation of him in terms of the first team is that we are quietly confident he can have a big impact as time goes on.
"At 6’3”, he is very good technically, can carry the ball and has a lovely left foot, but of course man-on-man combat is what he has to break through and be comfortable with. Overall, we are delighted to put him amongst our squad and believe that he can be a real positive for us.”