US President Donald Trump has nominated Amy Coney Barrett, a judge on the US Court of Appeals for the Seventh Circuit, to replace Ruth Bader Ginsburg on the Supreme Court.
At 48, the devout Roman Catholic would be the youngest justice on the bench if she is confirmed by the US Senate.
Mr Trump hailed Judge Barrett as "a woman of remarkable intellect and character", saying he had studied her record closely and found she was "very eminently qualified".
"Her qualifications are unsurpassed and her record is beyond reproach," Mr Trump said.
"This should be a straightforward and prompt confirmation. It should be very easy. Good luck. It's going to be very quick!"
Judge Barrett said she was "truly humbled" by the prospect of serving on the Supreme Court, adding she would be "mindful of who came before me".
"Justice Ginsburg began her career at a time when women were not welcome in the legal profession," she said.
"But she not only broke glass ceilings — she smashed them … She was a woman of enormous talent and consequence, and her life of public service serves as an example to us all," Judge Barrett said.
Mr Trump said the Senate would likely open hearings on October 12, and he expected a full Senate vote before the November 3 election.
Senate Judiciary Committee Chairman Lindsey Graham said in a statement on Saturday evening (local time) the committee would host a hearing for opening statements on October 12, followed by three to four days of questions and testimony.
"It's going to go fast. We're looking to do it before the election. So it's going to go very fast," Mr Trump said.
The hearings are part of an accelerated timeline as the Republican-controlled Senate seeks to vote on Mr Trump's nominee before the election and cement a 6-3 conservative majority on the court.
The death of Justice Ginsburg on September 18 has given Mr Trump and Senate Republicans the opportunity to install a 6-3 conservative majority on America's highest court.
It was Justice Ginsburg's dying wish that her seat be left vacant until after the election in November, but Mr Trump told his party it must move "without delay".
Shortly after Mr Trump's announcement, Democratic presidential nominee Joe Biden issued a statement urging the Senate to delay the appointment until "after the American people select their next president and the next Congress".
"The United States Constitution was designed to give the voters one chance to have their voice heard on who serves on the court," the statement said.
"That moment is now and their voice should be heard."
Conservative religious views
Before being appointed to her Seventh Circuit position in 2017, Judge Barrett was a legal scholar at Notre Dame Law School in Indiana.
She is a mother of seven children, two of whom are adopted.
Judge Barrett is known for her conservative religious views and has stated "life begins at conception".
She became a hero to conservative activists when Democratic senator Dianne Feinstein said at her 2017 confirmation hearing: "The dogma lives loudly within you."
Abortion rights groups predict that, if appointed, she will seek to overturn the landmark 1973 Roe vs Wade Supreme Court decision that legalised abortion nationwide.
Although she has not yet ruled directly on abortion, Judge Barrett twice signalled opposition to rulings that struck down Republican-backed Indiana abortion-related restrictions — one in 2018 requiring foetal remains to be buried or cremated after an abortion, the other in 2019 involving parental notification — voting to have those decisions reconsidered.
In June, Judge Barrett dissented when a three-judge panel ruled in favour of a challenge to Mr Trump's policy to deny legal permanent residency to certain immigrants deemed likely to require government assistance in the future. In January, the Supreme Court, powered by its conservative majority, allowed the policy to take effect.
She also authored a ruling that made it easier for college students who had been accused of sexual assault to challenge how their schools dealt with their cases.
Judge Barrett and her colleagues revived a lawsuit by a male student who had been suspended from Purdue University after sexual assault allegations. He accused the school of discriminating against him on the basis of his gender.
She wrote in the case it was plausible Purdue officials chose to believe the female accuser "because she is a woman" and to disbelieve the male student accused "because he is a man".
Judge Barrett previously served as a clerk for Supreme Court Justice Antonin Scalia, a stalwart conservative who died in 2016.
In a 1998 law journal article, she and another author said that Catholic judges who are faithful to their church's teachings are morally precluded from enforcing the death penalty and should recuse themselves in certain cases.
Abortion rights groups, worried about preserving the 1973 ruling that a woman has a constitutional right to have an abortion, point to a 2003 law journal article in which Judge Barrett argued that courts could be more flexible in overturning prior "errors" in precedent.
Judge Barrett has also spoken publicly about her conviction that life begins at conception, according to a 2013 article in Notre Dame Magazine.
Her writings also signal views on other contentious topics including healthcare. In a law review article published in 2017, she criticised conservative Chief Justice John Robert's major 2012 ruling preserving Obamacare.
"Chief Justice Roberts pushed the Affordable Care Act beyond its plausible meaning to save the statute," Judge Barrett wrote.