The Supreme Court announced that Kavanaugh will be sworn in today by Chief Justice John Roberts and retired Justice Anthony Kennedy, for whom Kavanaugh clerked.
A separate, public swearing-in ceremony is planned for 7:00 pm (2300 GMT) Monday in the White House's East Room. Justice Kavanaugh's nomination was approved by a vote of 50-48.
Kavanaugh's opponents raised concerns that he'd push the court further right, including possible sympathetic rulings for Trump.
Democrats also challenged Kavanaugh's honesty, temperament and ability to be nonpartisan after he fumed at last week's Judiciary hearing that Democrats had launched a "search and destroy mission" against him fueled by their hatred of Trump. Joe Manchin (D-W.Va.), who voted with the Republicans despite "reservations" about Kavanaugh's character and the accusations against him.
Yet Kavanaugh's pathway to confirmation seemed unfettered until Ford accused him of drunkenly sexually assaulting her in a locked bedroom at a 1982 high school gathering. Dianne Feinstein - possibly an erroneous reference to her bill to end family separations - before quickly calling her "Leaking Dianne Feinstein" and mocking her denial that she or her staff leaked a letter from Ford accusing Kavanaugh of sexual assault.
Flake initially announced he would vote for Kavanaugh, but requested a week-long delay to allow the FBI to investigate allegations of sexual misconduct made against the 53-year-old judge. "I do believe that she was assaulted". Kavanaugh followed her with testimony that was often emotional or angry, as he forcefully declared his innocence and assailed the accusations against him as the product of an orchestrated effort by the left to torpedo his nomination. Kavanaugh denied the accusations. Republicans emerged confident that the FBI investigation into the allegations unearthed no new corroborating details.
The Republican leader said he was talking with political strategists a day before Saturday's vote to confirm Kavanaugh and they told him voters were more excited by the court fight than by any other issues.
The prolonged nomination battle has roiled American politics and passions - the vote was disrupted on several occasions by angry protests from the gallery - but handed Trump one of the biggest victories of his presidency. Democrats were sharply critical of the investigation and the report that it produced, noting that the FBI had not interviewed either Blasey Ford or Kavanaugh.
By a vote of 50-48, the Senate gave a lifetime job to Kavanaugh, 53, after weeks of fierce debate over sexual violence, privilege and alcohol abuse that convulsed the nation just weeks before congressional elections on November 6.
Ahead of the vote, hundreds of people protested against Mr Kavanaugh's nomination at the US Capitol in Washington.
Collins, a key swing vote in the Senate, delivered a speech Friday afternoon affirming that she would vote to confirm Kavanaugh, who faced allegations of sexual assault. She said on the Senate floor Friday evening that Kavanaugh is "a good man" but his "appearance of impropriety has become unavoidable".
Republicans had accused Democrats of seeking to delay the confirmation of Kavanaugh in the hope that they will make gains in the mid-term elections in November and stop his appointment altogether.
Republican Senate Majority Leader Mitch McConnell, who has railed against Kavanaugh's critics, said he was "proud" of his colleagues and predicted a bright future for his party.
Several hundred protesters, a lot of them women, barged through barricades to lay claim to the front steps of the US Capitol.
Before the vote, Senate Minority Leader Chuck Schumer, a Democrat from NY, urged Americans who were dissatisfied with the confirmation to go to the polls in November and "vote".
Kavanaugh's nomination seals a conservative majority on the nine-seat high court, possibly for decades to come. They went through it, and they went through it seven times. The names of the senators were called one by one, with each senator standing to cast his or her vote.
Alaska's Lisa Murkowski, the only Republican to oppose the nominee, voted "present", offsetting the absence of Kavanaugh supporter Steve Daines of Montana, who was attending his daughter's wedding.