Under questioning on Wednesday from Democratic Senator Patrick Leahy of Vermont, President Donald Trump’s choice for the high court offered no view on the pardon issue.
Multiple investigations are looking into Mr Trump’s taxes, his businesses and his associates.
Ms Barrett would not offer her thoughts on whether Mr Trump would be able to pardon himself.
But she agreed with Mr Leahy’s assertion “no one is above the law”.
Ms Barrett is in her third day of hearings and has repeatedly refused to say how she would rule on various issues, including abortion and the Affordable Care Act.
Republican senators are moving at a breakneck pace to confirm Ms Barrett before the November 3 election.
Democrats say the process is being rushed.