Shakeil Thibou was convicted of murdering Cher Maximen at the Old Bailey last month.
On Friday, the 20-year-old was jailed for life with a minimum term of 29 years.
Ms Maximen, 32, was with friends when she became caught up in a fight involving multiple men – and died in hospital from her injuries six days later.
Judge Philip Katz KC said Thibou’s “brazen” attack was carried out in front of families and the police.
The defendant wore a medical face mask and blue beanie hat in the dock, and looked straight ahead throughout the hearing.
Judge Katz told Thibou: “The police were totally outnumbered as the violence spun out of control. Just watching the bodyworn footage was terrifying.
“When violence broke out, you were quick to move to join in. You were so fired up that you didn’t hesitate to use your knife. You were so brazen that it was carried out in front of police officers.”
His older brother Sheldon, 25, was found guilty of violent disorder and assaulting PC Oliver Mort, who tried to intervene.
A third brother, 22-year-old Shaeim, was cleared of violent disorder but convicted of assaulting the police officer. They will be sentenced separately.
Following Thibou’s conviction, Detective Chief Inspector Alex Gammampila had said: “Cher was a loving mother who went to Notting Hill Carnival to enjoy what should have been a carefree day … her life was ended in the most senseless way.
“In stark contrast, Shakeil Thibou went to Carnival not to be part of the celebration, but to engage in violence. Why else would he have arrived armed with a large knife and seeking confrontation?”
The attack, which was caught on camera, happened just off the parade route on 25 August last year.
Cher’s relative TJ Jacobs, who is godmother to her daughter, said: “What happened to us has completely turned our lives upside down. Losing Cher has filled our hearts with immeasurable sadness.
“This senseless act of violence has cut short a life that had so much more to offer the world and was only just beginning to blossom.”
Speaking to Sky News, her family described her as a vivacious young woman who grew up in Bristol and then London, finding her feet working with people in music and entertainment.
Cher’s cousin Lawrence Hoo said: “It’s just this energy she had, she lit up the room. If you walked into a space, you’d know that Cher was there. Her energy itself would fill the room. She was a very bright light.”
Mr Hoo said the idea of the toddler witnessing her mother on the ground punctuates the sadness the family feel with anger.
“The feeling of loss is overwhelming, but so is the feeling of rage,” he said. “She [Cher’s daughter] is aware that on that day, something happened to her mother.”
