"Chelsea #Manning has filed her request for a presidential pardon for her 35 year prison sentence as #WikiLeaks source," Ed Pilkington, a reporter for the British newspaper The Guardian, said in a Twitter message.
Shortly after his sentencing in August, Bradley Manning revealed he had taken on the identity of a woman, Chelsea Manning.
David Coombs, Manning's attorney, indicated at the sentencing his client would ask President Obama for a pardon.
Coombs said at the time that Manning would say, "If you deny my request for a pardon, I will service my time knowing that sometimes you have to pay a heavy price to live in a free society."
In a subsequent tweet, Pilkington quoted Manning as saying in the pardon submission, "The decisions that I made in 2010 were out of concern for my country & the world we live in."
Manning must serve at least 11 to 12 years of his sentence before he can be considered for parole. He has already served more than three years.
Obama has granted 39 pardons since March.