Alice Marie Johnson, a 63-year-old from Tennessee, has already served more than 20 years in prison on drug conspiracy and money laundering charges. Johnson "has been a model prisoner over the past two decades" White House spokeswoman Sarah Sanders said in a statement.
Sanders said that while "this administration will always be very tough on crime, it believes that those who have paid their debt to society and worked hard to better themselves while in prison deserve a second chance."
While Johnson was deserving of clemency, the manner in which her case was brought to Trump's attention was unprecedented and raises fairness concerns, said Margaret Love, a lawyer who formerly served as the US Pardon Attorney in the Justice Department.
"Never in history has this been done," Love said.
Kardashian West personally lobbied Trump and also met with Jared Kushner, a senior adviser to Trump who has spearheaded efforts at sentencing and prison reform for the administration.
A White House official familiar with the clemency process said that Trump continues to examine the cases of people whom he believes have been victims of the criminal justice system.
Trump is still considering pardoning lifestyle maven Martha Stewart, who was convicted in an insider trading case, and commuting the sentence of former Illinois Governor Rod Blagojevich, serving 14 years on felony corruption charges, along with several others, the White House official said.
Stewart and Blagojevich both have ties to Trump's former "Apprentice" TV shows, but the White House has denied that Trump is only considering pardons for well-known figures.
"President Trump saved Alice Johnson's life today," said Brittany K. Barnett, a lawyer for Johnson.
Most clemency requests are handled by the Justice Department's Office of the Pardon Attorney, which receives thousands of requests from prisoners every year, said Mark Osler, a law professor at the University of St. Thomas in Minnesota. Applications are usually reviewed by multiple government attorneys before being shared with the president.