In the Rose Garden ceremony, Trump said Americans would see in Gorsuch "a man who is deeply faithful to the Constitution of the United States" and predicted greatness for the 49-year-old former appeals court judge from Colorado.
"I have no doubt you will go down as one of the truly great justices in the history of the U.S.," Trump said. The president noted that the successful nomination came during his first 100 days in office and added: "You think that's easy?"
Gorsuch, who restores the court's conservative majority, was sworn in during the ceremony by Justice Anthony Kennedy, for whom he once served as a law clerk. It was the second of two oaths — the first was conducted privately in the Justices' Conference Room by Chief Justice John Roberts.
In remarks in the Rose Garden, Gorsuch said he was humbled by his ascendance to the nation's high court and thanked his former law clerks, saying of his former law clerks, "your names are etched in my heart forever."
Gorsuch promised to be a "faithful servant of the Constitution and laws of this great nation."
He fills the nearly 14-month-old vacancy created after the death of the late Justice Antonin Scalia, who anchored the court's conservative wing for nearly three decades before he died unexpectedly in February 2016. In nominating Gorsuch, Trump said he fulfilled a campaign pledge to pick someone in the mold of Scalia.
During 11 years on the federal appeals court in Denver, Gorsuch mirrored Scalia's originalist approach to the law, interpreting the Constitution according to the meaning understood by those who drafted it. Like Scalia, Gorsuch is a gifted writer with a flair for turning legal jargon into plain language people can understand.
Gorsuch will be seated just in time to hear one of the biggest cases of the term: a religious rights dispute over a Missouri law that bars churches from receiving public funds for general aid programs.
His 66-day confirmation process was swift, but bitterly divisive. It saw Senate Republicans trigger the "nuclear option" to eliminate the 60-vote filibuster threshold for Gorsuch and all future high court nominees. The change allowed the Senate to hold a final vote to approve Gorsuch with a simple majority.
Most Democrats refused to support Gorsuch because they were still seething over the Republican blockade last year of President Barack Obama's pick for the same seat, Merrick Garland. Senate Republicans refused to even hold a hearing for Garland, saying a high court replacement should be up to the next president.
The White House swearing-in ceremony was a departure from recent history. Justices Sonia Sotomayor and Elena Kagan were both sworn in publicly at the Supreme Court. Former Justice John Paul Stevens has argued that holding the public ceremony at the court helps drive home the justice's independence from the White House.