A Frontiersman on a fur trading expedition in the 1820s fights for survival after being mauled by a bear and left for dead by members of his own hunting team.
Set in an indeterminate year of the 1820s, the opening scene shows Hugh Glass (Leonardo DiCaprio) speaking to his son Hawk (Forrest Goodluck) in an Indian language, telling him that even though he is scared and wants his trouble to be over, he must fight as long as he can grab a breath. As we hear Glass' voice, we see images of Glass with his wife and son, his home being set on fire, and him holding his wife in his arms.
Glass and Hawk are walking through a river with other men from their hunting party as they stalk wildlife. They live on a settlement with other fur-trappers. They are led by their captain, Andrew Henry (Domhnall Gleeson). A man from their party walks into the settlement and collapses forward with an arrow in his back. Another man is shot in the neck with an arrow and falls into the campfire. The hunting party is attacked by a tribe of local natives who are Arikara Indians. The men fire back with their rifles. Glass is attacked and nearly choked to death, but one of his men rescues him. The surviving men gather their furs and materials toward a boat to make their escape.
It is learned that the Arikaras are looking for the chief's daughter, Powaqa, thinking that one of the men from the hunting party may have taken her.
The men seek out a new settlement. Hawk is antagonized by John Fitzgerald (Tom Hardy) for his race (Hawk is half-Indian on his mother's side), but Glass quickly defends his son and tells him not to retaliate against Fitzgerald.
Glass is later separated from the party in the woods. He comes across a grizzly bear and her cubs, and he is quickly attacked by the larger bear. The bear claws and bites Glass, throwing him around as Glass tries to defend himself. He manages to shoot the bear, but it doesn't kill her. She attacks again and Glass gets his knife, stabbing it several times as they both tumble down a hill. Glass lands in a gully and the dead bear lands on top of him. The men later find Glass and try to tend to his deep wounds.