Barack Obama commuted much of her 35-year sentence in the final days of his presidency
Former President Barack Obama commuted much of her 35-year sentence in January.
Manning left the military prison at Fort Leavenworth in Kansas early Wednesday, according to a photo she posted on Instagram.
"First steps of freedom!!" she wrote under a photo of her legs and feet clothed in civilian attire.
"#chelseaisfree", she added.
Chelsea Manning, who was formerly known as Bradley Manning, was convicted of providing whistleblower website Wikileaks with tens of thousands of classified documents, including sensitive diplomatic cables, in 2010.
She was arrested that year, and sentenced in 2013 to the longest prison term ever handed down for a leak conviction.
Manning was serving as an intelligence analyst in Iraq when she made the controversial disclosures.
Manning, who expressed her desire to live as a woman while in prison and has been receiving hormone therapy, will remain on active duty while she appeals her court marshal conviction.
She said earlier this year that she was planning on returning to Maryland upon her release.