The 29-year-old transgender US Army private, born Bradley Manning, will be freed on 17 May instead of her scheduled 2045 release, the BBC reports.
She was sentenced to 35 years in 2013 for her role in leaking diplomatic cables to the anti-secrecy group.
The leak was one of the largest breaches of classified material in US history.
The White House had suggested in recent days it was open to commuting Manning’s sentence.
She twice attempted suicide last year at the male military prison where she is being held at Fort Leavenworth, Kansas.
Manning also went on a hunger strike last year, which ended after the military agreed to provide her with gender dysphoria treatment.
In one of his final acts as president, Obama granted commutation of sentences to 209 individuals and pardons to 64 others.
Manning also went on a hunger strike last year, which ended after the military agreed to provide her with gender dysphoria treatment.
In one of his final acts as president, Obama granted commutation of sentences to 209 individuals and pardons to 64 others.
Manning’s lawyer, David Coombs, told the BBC the commutation would be a great relief to his client.
“It really is a great act of mercy by President Obama,” said Coombs.
Journalist Glenn Greenwald, who broke the story of Edward Snowden’s leaks, told the BBC: “I don’t think she (Manning) should have spent a single day in prison.”
He said she was “heroic and has inspired millions of people around the world”.