El Shafee Elsheikh, 34, who grew up in London, showed no emotion as judge Thomas Selby Ellis delivered his verdict at Alexandria District Court, Virginia, while members of his victims’ families
Elsheikh was given a life sentence for each of the eight counts he was convicted of in April, which are due to run concurrently.
The counts related to his role in a hostage-taking scheme which involved torturing, beating and executing prisoners.
Raj Parekh, representing the families, said Elsheikh – known to prosecutors as “Ringo” – remained “defiantly remorseless and unrepentant”.
He noted that the jihadist had made no effort to meet victims’ families, like his co-defendant Alexanda Kotey.
Addressing the jihadist, judge Ellis said: “The behaviour of this defendant and his co-defendant can only be described as horrific, barbaric, brutal and callous.
“This is a significant episode in the history of our country and our justice system.”
The court heard statements from some of the victims’ loved ones, including those of US journalist James Foley.
His mother, Diane Foley, told Elsheikh his “hatred overtook your humanity” as she delivered her victim impact statement, noting that it was the eight-year anniversary of her son’s death.
“This trial has revealed the horrific human rights crimes you committed while part of Isis,” she said, addressing him directly.
“Your hatred overtook your humanity.”
Becoming audibly emotional, Ms Foley continued: “Knowing Jim, my suffering and that of our family would have given Jim the deepest pain.
“(But) Jim would say ‘Elsheikh, you did not kill me. I am alive in my family and friends and their friends.
“I live on in those who survived your inhumanity. I am alive in all those who aspire to moral courage.
“In many ways I am more alive than I have ever been’.”
Addressing Elsheikh again, she added: “I pity you for choosing hatred and for succumbing to a false theology.”
Elsheikh sat wearing a green, prison-issue jumpsuit, with white trainers and a black face-covering, and wore glasses.
At times he appeared to turn his head in the direction of those reading out their victim impact statements.
Judge Thomas Selby Ellis was due to allow the jihadist the opportunity to speak before passing sentence on him, which he later declined.
Ms Foley was joined outside of court by the parents of US humanitarian worker Peter Kassig, Ed and Paula Kassig.
Elsheikh was one of a gang of four Isis militants branded The Beatles due to their British accents.
The cell was said to be made up of ringleader Mohammed Emwazi, known as Jihadi John; Aine Davis; Alexanda Kotey and Elsheikh.
Elsheikh was captured alongside Kotey in Syria in 2018 by the US-supported Syrian Democratic Forces while trying to escape to Turkey.
Last year, Kotey pleaded guilty to eight counts relating to his involvement, while Davis was jailed in Turkey before being deported to the UK last week and Emwazi was killed in a drone strike.
Kotey was given the same sentence of eight concurrent life sentences, also by judge Ellis, at the same court in April.