WASHINGTON — The Senate on Thursday confirmed Judge Ketanji Brown Jackson to the Supreme Court, making her the first Black woman to be elevated to the pinnacle of the judicial branch in what her supporters hailed as a needed step toward bringing new diversity and life experience to the court.

Overcoming a concerted effort by Republicans to sully her record and derail her nomination, Judge Jackson was confirmed on a 53-to-47 vote, with three Republicans joining all 50 members of the Democratic caucus in backing her.

The vote was a rejection of Republican attempts to paint her as a liberal extremist who had coddled criminals. Dismissing those portrayals as distorted and offensive, Judge Jackson’s backers saw the confirmation as an uplifting occasion for the Senate and a mark of how far the country had come.

Judge Jackson, whose parents attended segregated schools, has two degrees from Harvard University and, at 51, is now in line to replace Justice Stephen G. Breyer when he retires at the end of the court’s session this summer, making her a justice in waiting.

“Even in the darkest times, there are bright lights,” Senator Chuck Schumer, Democrat of New York and the majority leader, said on the Senate floor. “Today is one of the brightest lights. Let us hope it’s a metaphor, an indication of many bright lights to come.”

He added, “How many millions of kids in generations past could have benefited from such a role model?”

At the Capitol, the galleries, closed for much of the pandemic, were filled with supporters on hand to witness the historic vote. The chamber erupted in cheers, with senators, staff and visitors all jumping to their feet for a lengthy standing ovation, when the vote was announced.

“After weeks and weeks of racist, misogynistic and stomach-churning attacks, we cannot wait to finally call her Justice Jackson,” said Derrick Johnson, the president of the N.A.A.C.P., describing the moment as one of “enormous consequence to our nation and to history.”

Not everyone shared in the joy of the day. As applause echoed from the marbled walls, Senator Mitch McConnell, Republican of Kentucky and the minority leader, turned his back and slowly walked out, as did most of the few Republicans remaining on the floor, leaving half of the chamber empty as the other half celebrated in a stark reflection of the partisan divide.

“When it came to one of the most consequential decisions a president can make, a lifetime appointment to our highest court, the Biden administration let the radicals run the show,” Mr. McConnell had said earlier, making one last argument against Judge Jackson, whose nomination he framed as an example of extremists taking control of the Democratic Party. “The far left got the reckless inflationary spending they wanted. The far left has gotten the insecure border they wanted. And today, the far left will get the Supreme Court justice they wanted.”

Three Republicans — Senators Susan Collins of Maine, Lisa Murkowski of Alaska and Mitt Romney of Utah — crossed party lines to vote to confirm Judge Jackson, lending a modicum of bipartisanship to an otherwise bitterly polarized process.

It was a sign of the deeply divided times that winning over three Republicans was considered something of a victory. When Justice Breyer — nominated by President Bill Clinton — was confirmed in 1994, it was by a 87-to-9 vote, in line with prevailing sentiment at the time that presidents were entitled to their chosen justice, provided the nominee was qualified and temperamentally suited to the job.

But in recent years, Supreme Court confirmation fights have become political blood sport, featuring combative televised hearings in which senators of the opposite party seek to tarnish the reputation of the president’s nominee, while making partisan appeals to their core supporters.

Confirmations have fallen almost entirely along partisan lines. Democrats uniformly opposed Justice Amy Coney Barrett, President Donald J. Trump’s third nominee to the court, who was rushed through just before the 2020 election, and only one of them voted to confirm his second, Justice Brett M. Kavanaugh, whose explosive hearings included an allegation of sexual assault.

In 2017, Justice Neil M. Gorsuch, Mr. Trump’s first nominee, received three Democratic votes — the same level of bipartisanship as Judge Jackson — but his nomination came only after Republicans had blocked President Barack Obama from filling a Supreme Court seat a year earlier, refusing to grant a hearing to his nominee, Merrick B. Garland, during an election year.

Judge Jackson’s confirmation was a major achievement for President Biden, who had promised at a low point during his 2020 primary campaign that he would appoint a Black woman to the Supreme Court at his first opportunity. As a former public defender, Judge Jackson is the leading example of the emphasis the administration has put on expanding not only the personal diversity of the courts, but the professional as well. She will be the first ever public defender to serve as a Supreme Court justice.

Vice President Kamala Harris, the first Black woman to hold the position and one of just 11 Black senators in American history, presided over the vote — one historic figure presiding over the elevation of another — as senators stated their positions from their desks in a reflection of the magnitude of the moment. More than a dozen members of the Congressional Black Caucus, including Representative Hakeem Jeffries, Democrat of New York, and Representative Joyce Beatty, Democrat of Ohio, clustered on the Senate floor to mark the occasion.

At the White House, Mr. Biden and Judge Jackson watched the vote together from the Roosevelt Room, embracing and taking selfies in front of a television screen displaying the final vote count. Officials said the two would appear at an event on Friday to mark Judge Jackson’s confirmation, though she will not be sworn in for months.

“I’m overjoyed, deeply moved,” Ms. Harris told reporters after the vote. “There’s so much about what’s happening in the world now that is presenting some of the worst of this moment and human behaviors. And then we have a moment like this.”

That moment was orchestrated by the White House and Democrats, who, given their precarious hold on the evenly split Senate, wanted to move as quickly as they could after Justice Breyer announced his retirement plans in February to put in place a successor.

Mr. Schumer had urged the White House to move swiftly in filling the seat even before it became vacant, warning that he was only one illness or senatorial absence away from losing his majority and the ability to deliver a confirmation to the president.

“One member and we don’t have it,” Mr. Schumer said in an interview, recounting his message to White House officials. “I wanted to be fair, but I wanted to be expeditious. We couldn’t stretch this out.”

Faced with a historic pick who would not change the ideological divide of the court, top Senate Republicans initially promised a respectful review of her record to show they could scrutinize a judicial nominee without personal attacks.

But as the hearings approached, Republicans sharpened their tone.

Mr. McConnell took strong issue with her refusal to take a position on proposals to add seats to the Supreme Court — a priority of progressive groups that were enthusiastic backers of Judge Jackson.

Senator Josh Hawley, a Missouri Republican with presidential ambitions, claimed misleadingly that a review of her sentencing record in child sex abuse cases showed a pattern of handing down penalties lighter than recommended by prosecutors.

Republicans also faulted her for representing terror detainees at the military prison in Guantánamo Bay, Cuba, as an appointed public defender and signing court papers that accused President George W. Bush of committing war crimes for torturing detainees.

“She is an extreme outlier on the question of crime,” Senator Ted Cruz, Republican of Texas, told reporters at a news conference in the Capitol not long before the vote, reiterating attacks that have been debunked by several independent analysts, who note that Judge Jackson’s sentencing record is well within the mainstream.

Senator Marsha Blackburn, Republican of Tennessee, claimed that “the dark money leftist groups” supporting Judge Jackson were “trying to push this agenda of woke education.”

The few Republicans who backed Judge Jackson rejected such criticisms, as well as what Ms. Murkowski called the “corrosive politicization” of the Supreme Court confirmation process.

While Democrats had the votes to confirm Judge Jackson on their own if their caucus united behind her, they wanted some Republican backing, particularly for a historic pick. Senator Richard J. Durbin, Democrat of Illinois and the chairman of the Judiciary Committee, worked quietly to bring some Republicans on board and the White House made Judge Jackson available to potential G.O.P. supporters both before and after the hearings.

A turning point came last week when Ms. Collins announced she would back the nominee after a second sit-down with the judge to clear up some issues that arose during the hearings. Ms. Murkowski, whose decision was complicated by a difficult re-election race, and Mr. Romney soon followed.

By Thursday, the outcome of the vote was not in doubt, but it dragged on for almost 30 minutes because Senator Rand Paul, Republican of Kentucky, was not present on the floor. Once he had arrived, Mr. Paul cast his “no” vote from the Senate cloak room because he was dressed too casually to meet the jacket-and-tie dress code for the chamber.

When Ms. Harris called the vote, Mr. Romney stood to join Democrats in applauding, but many Republicans had already departed.

The dismissive attitude was in keeping with the hostile treatment Judge Jackson received during her confirmation hearings, in which she was questioned about her religion, her views on critical race theory, and even the definition of “woman.”

But on Thursday, her supporters were ebullient.

“Nobody’s going to steal my joy,” Senator Raphael Warnock, Democrat of Georgia, said in remarks ahead of the vote. “I’m a senator, I’m a pastor. But beyond all that, I’m the father of a young Black girl.” He said Judge Jackson’s ascension to the nation’s highest court exemplified “the promise of progress on which our democracy rests.”

Emily Cochrane contributed reporting.