She has now signed a document agreeing to plead guilty to misdemeanour disorderly conduct, which would mean she would avoid jail.
The pipeline project has been highly controversial and drawn huge protests.
Native Americans say it will desecrate sacred land and damage the environment.
Woodley, who livestreamed her arrest on Facebook, initially pleaded not guilty to criminal trespass and engaging in a riot.
Her plea deal, which is awaiting the approval of a judge, would see her serve a year's unsupervised probation and forfeit a $500 (£400) bond.
The actress, who is also known for roles in The Fault in Our Stars and Big Little Lies, was scheduled to stand trial on Friday.
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