US President Donald Trump nominated Judge Amy Barrett to the Supreme Court on Saturday, hailing her as 'a woman of remarkable intellect and character', adding he had studied her record closely before making the decision.
Barrett, former clerk to the late Justice Antonin Scalia, said she was "truly humbled" by the nomination.
Political observers say by picking a Conservative, Trump hopes his re-election effort will get a much needed boost.
If confirmed by the Senate, 48-year-old Barett would fill the seat vacated by liberal icon Ruth Bader Ginsburg. It would be the sharpest ideological swing at the US Supreme Court in three decades.
Amy Barett would be the sixth justice on the nine-member court to be appointed by a Republican president, and the third of Trump's first term in office.