He made a exceptional counsel to withhold a high profile case that contributed to Libby's verdict in 2007.
Democrats reacted sharply to Trump's pardoning.
Trump's pardon has been under consideration for several months, two people familiar with the president's thinking said.
Former Ambassador Joseph Wilson called Trump a "vile and despicable individual."Bolton was a key Bush administration advocate, along with Cheney and Libby, of the 2003 US invasion of Iraq.
A spokesman for Bush said the former president was "very pleased" for Libby and his family. As Arthur Herman wrote in Commentary, an overzealous special prosecutor framed Libby, a dedicated public servant (and a friend of this writer). "Comey appointed the special counsel, Patrick Fitzgerald, in the Scooter Libby case".
"He has basically given his seal of approval on things he claims to have been against, i.e. the war on Iraq", Wilson told Tur.
The Bush administration leaked the name of Wilson's wife, Valerie Plame, a covert Central Intelligence Agency agent, to the press in its attempts to undercut Wilson. That was taken as proof that Libby must of have raised Plame's work at the Central Intelligence Agency.
"Perjury before a grand jury is a pardonable offense". Paul Krugman denounced his "deadly narcissism" in the New York Times, by which he means that Trump values his own opinion more than that of Krugman.
As the clock was running out on George W. Bush's presidency in late 2008, the president and the vice president edged closer to a showdown.
Trump, who often rails against disclosures to the news media but was a longtime anonymous source himself, appears to have chosen to forgive Libby for his role in the disclosure of CIA Agent Valerie Plame's idenitfication.
' This is simply false.
That's according to a person familiar with the president's decision who said the announcement could come as early as Friday. He granted one a year ago for former Arizona sheriff Joe Arpaio, who was awaiting sentencing for contempt of court.
"I am grateful to day that President Trump righted that incorrect by issuing Scooter, & rdquo with the pardon".
Plame noted that Libby had been convicted of obstruction of justice and perjury "in a fair trial" in which both former President George W. Bush and former Vice President Dick Cheney had given testimony. The new sentence still required Libby to complete a two-year probation, pay $250,000 fine, and perform 400 hours of community service.
"One would always rather not be a felon than be a felon", Lisa Kern Griffin, a law professor at Duke University, said in an interview.
"In light of these facts, the President believes Mr. Libby is fully worthy of this pardon".
"It's not about me, it's absolutely not about "Scooter" Libby," she said.