Richard the Lionheart (Ian Hunter), King of England, is taken captive in 1191 by Leopold V, Duke of Austria while returning from the Holy Land. Richard’s treacherous brother Prince John (Claude Rains) usurps the throne and proceeds to oppress the Saxons, raising taxes to secure his own position.
Only the Saxon nobleman Sir Robin of Locksley (Errol Flynn) opposes him. Robin acquires a loyal follower when he saves Much the Miller’s Son (Herbert Mundin) from being arrested for poaching by Sir Guy of Gisbourne (Basil Rathbone). At Gisbourne’s castle, Robin boldly tells Prince John and his Norman followers, and the contemptuous Lady Marian Fitzwalter (Olivia de Havilland), that he will do all in his power to restore Richard to the throne. Robin escapes, despite attempts by John’s men to stop him.
Robin, Much, and friend Will Scarlet (Patric Knowles) take refuge in Sherwood Forest and recruit Little John (Alan Hale, Sr.), while other men join their growing band, including the rotund Friar Tuck (Eugene Pallette), an accomplished English swordsman.
Branded as outlaws, Robin binds his men by an oath: to fight for a free England until the return of Richard, to rob the rich and give to the poor, and treat all women with courtesy, “rich or poor, Norman or Saxon”. Robin and his band begin a guerrilla war against Prince John, systematically killing the Prince’s tax collectors and any Norman nobleman or man-at-arms who abuses his power.
Robin and his men capture a large party of Normans transporting tax money extorted from the Saxons. Among Robin’s “guests” are Sir Guy of Gisbourne, the cowardly Sheriff of Nottingham (Melville Cooper), and the Lady Marian. Disdainful of Robin at first, Marian comes to accept his good intentions and to see the reality of Norman brutality. Robin allows the humiliated Sir Guy and the Sheriff to leave Sherwood, telling them that they have Lady Marian’s presence to thank for their lives being spared.
The Sheriff devises a cunning scheme to capture Robin by announcing an archery tournament with the prize of a golden arrow to be presented by the Lady Marian. All goes as planned: Robin wins the prize and is taken prisoner and is sentenced to hang.
Marian helps Robin’s men rescue him, and he later scales a high castle wall to thank her. Each pledges their love for each other, but Marian declines to leave with him, believing she can best help by staying to be a spy for the men of Sherwood.
King Richard and several trusted knights have returned to England, disguised as monks. At a roadside inn, the Bishop of the Black Canons (Montagu Love) discovers them and alerts Prince John and Gisbourne. Dickon Malbete (Harry Cording), a degraded former knight, is given the task of disposing of Richard in return for the restoration of his rank and Robin’s manor and estate.
Marian overhears their plot and writes a note to Robin, but Sir Guy finds it and has her arrested, pending trial and execution. Marian’s confidant, Bess (Una O’Connor), sends Much to warn Robin. On his way, he intercepts and kills Dickon but is wounded in the process.
As Richard and his liegemen journey through Sherwood Forest, they are stopped by Robin and his men. Richard assures Robin that he is traveling on the King’s business; when asked if he supports Richard, the incognito King replies, “I love no man better”. He accepts Robin’s invitation to dine with the men of Sherwood and Robin’s rebuke for him not staying in England instead of fighting in foreign lands.
Will finds the injured Much, who tells Robin of Marian’s peril and that Richard is now in England. Robin orders a thorough search to find Richard and bring him to Robin for safety. Now certain of their loyalty, Richard reveals his identity.
Robin devises a plan to sneak into Nottingham Castle. He coerces the Bishop of the Black Canons to include his men, disguised as monks, in his entourage for John’s coronation. In the great hall Richard reveals himself to the assembled nobles, and a huge melee breaks out. Robin and Sir Guy engage in a prolonged sword fight, ending with Gisbourne’s death. Robin releases Marian from her prison cell, and Prince John’s men, now defeated, throw down their swords, shields, and banners in surrender.
Richard exiles John and his followers for his lifetime and pardons the outlaws. He elevates Robin Hood to be Baron of Locksley and Earl of Sherwood and Nottingham, and commands that Robin marry the Lady Marian. With Marian now by his side, from across the great hall, Robin replies with enthusiasm, “May I obey all your commands with equal pleasure, Sire!”