Trump prefaced the reveal with a brief address, saying that like President Reagan before him, he was looking for "judges who apply the Constitution as written".
Mr Trump added: "He is a brilliant jurist with a clear and effective writing style, universally regarded as one of the finest and sharpest legal minds of our time".
"Judge Kavanaugh has impeccable credentials, unsurpassed qualifications and a proven commitment to equal justice under the law", Trump said.
Senate Majority Leader Mitch McConnell, R-Kentucky, who once held a court seat open for almost a year before the 2016 election to keep former President Barack Obama from filling it, lambasted Democrats for announcing their opposition before Trump had decided on a nominee. Hardiman is one of four judges thought to be President Donald Trump's top contenders to fill a vacancy on the Supreme Court.
Trump is hoping to replicate his successful nomination of Justice Neil Gorsuch a year ago.
A Maryland native whose mother was a public school teacher who went on to serve as a state judge in Maryland, Kavanaugh got his undergraduate and law degrees from Yale University.
A group of Democratic senators from Republican-leaning states - lawmakers who could be pivotal in the confirmation fight - declined Trump's invitation to attend the White House announcement.
Democrats are warning that Trump's nominee would jeopardize some of progressives' most important policy priorities in recent decades - including rulings that legalized abortion and same-sex marriage, as well as former President Barack Obama's health care law. A more conservative majority could be more willing to uphold state restrictions on abortion, if not overturn the 45-year-old landmark Roe v. Wade decision that established a woman's constitutional right to abortion. Besides McGahn, he has the support of some Republicans who admire his record as a lawyer working with independent counsel Ken Starr in the investigation of President Bill Clinton and later in the George W. Bush White House as well as his conservative record as a judge. Republicans now control that number of Senate seats, although one of their number, Senator John McCain, is at home in Arizona battling cancer.
"No president has ever consulted more widely, or talked with more people from more backgrounds to seek input abut a Supreme Court nomination". Kethledge, 51, is a judge for the Cincinnati, Ohio-based 6th U.S. Circuit Court of Appeals, while Hardiman, 52, serves on the Philadelphia-based 3rd U.S. Circuit Court of Appeals - also appointed by Bush. Senate Majority Leader Mitch McConnell has said the Senate will vote on the court nominee in the fall. He was in the running previous year for the Supreme Court seat left by the death of Justice Antonin Scalia.
White House spokesman Raj Shah said in a statement that Kyl "has agreed to serve as the Sherpa for the President's nominee to the Supreme Court".
"I'll exercise the judicial power with modesty and restraint", Kavanaugh said at his swearing-in ceremony.
Three Democrats who were invited but declined were Sens. After his renomination, the Senate voted 57-36 in 2006 to confirm him.