Manchester United have confirmed their defender has completed a loan switch to Leeds United on 7 August.
The 20-year-old came up through the Red Devils' youth system and made his first team debut in November 2015, when Louis van Gaal was in charge at Old Trafford. However, he was not given a chance in the first team last season by the Dutchman's successor Jose Mourinho.
United's current manager did not include Borthwick-Jackson in his squad for the 2017 pre-season. Leeds United manager Thomas Christiansen admitted that he watched the player in action on few occasions.
Borthwick-Jackson spent the first half of the last campaign on loan at Wolverhampton Wanderers. He will now spend the 2017/18 season on loan at Elland Road.
A statement on United's official website read, "Manchester United defender Cameron Borthwick-Jackson has joined Championship outfit Leeds United on a season-long loan for the 2017/18 campaign."
"Cameron joins a Leeds side that began their Championship campaign on Sunday with a hard-fought 3-2 away win at Bolton Wanderers, and his arrival has bolstered Thomas Christiansen's squad ahead of their Wednesday night Carabao Cup clash against Port Vale. We wish him well for the season ahead."
Borthwick-Jackson becomes Leeds' 11th signing of the summer transfer window as the White further looks to bolster their squad for the new season. Christiansen admitted the championship side are still looking to add more new faces to their squad this summer.