Ellis (Tye Sheridan) and Neckbone (Jacob Lofland) are two fourteen-year old boys living in De Witt, Arkansas. Finding a boat that was stuck on a tree in the middle of an island led the two friends into an encounter with a strange man who called himself Mud (Matthew McConaughey). With Mud promising to give them the boat, Ellis and Neck agreed to help him live while he waited for his lover, Juniper (Reese Witherspoon), to come and go with him. However, things aren't so simple as that. Bounty hunters began to visit the town looking for a murderer, and the truth about Mud began to unveil.
Mud contains examples of these tropes:
- Amicable Exes: In the end, Mud and Juniper part ways as friends, and The last conversation between Ellis and his father, where the latter instructs his son to be good to his mother, implies that Senior had come to understand his wife's reasons for leaving him.
- Big Damn Heroes: Tom finally shows off his sniping ability in the climax, saving Mud, Ellis, and Ellis' parents.
- Bittersweet Ending: Mud and Ellis both Did Not Get the Girl, but the former manages to escape his pursuers and is ready to start a new life while the latter has come to terms with his parents' divorce and has matured in regards of love.
- Character Title: The movie is titled after Mud, though he shares the protagonist role with Ellis.
- Coming-of-Age Story: The film is about Ellis growing up through his adventure with Mud.
- Cycle of Revenge: Mud murdered Juniper's Bastard Boyfriend to avenge his abuse to her and the boyfriend's crime syndicate of a family are now hunting Mud down.
- Deserted Island: A boat got stranded in the middle of one in the Arkansas River. The plot started with the boys meeting with Mud there.
- Exact Words: Mud promised Neckbone his gun in exchange of helping him prepare the boat to escape. He does give the boy the gun, but not the bullets.
- Foil: Mud is essentially what Ellis would become if he hadn't matured beyond his notions on romance.
- Gadgeteer Genius: Neckbone built his own motorcycles and later helps Mud rebuild the boat.
- Heroic BSoD: Mud, after Juniper decides to ditch him, and Ellis, after finding out that May never takes his feelings seriously and that Juniper and Mud have given up their relationship.
- Jerk with a Heart of Gold: Nobody in the cast is a completely nice person. Each has their share of selfishness and bad deeds, but they are able to show kindness from time to time.
- Two First Names: May Pearl, Ellis' crush, and Mary Lee, Ellis' mother. The coincidence is Lampshaded by his father.
- What the Hell, Hero?: Tom berates Mud for involving Ellis and Neck in his problem.