Rollo Duke of Normandy is a play written in collaboration by John Fletcher, Philip Massinger, Ben Jonson, and George Chapman. It was probably first written c. 1617, by Fletcher and Jonson, then revised c. 1630 by Massinger, Field, and/or Daborne. It is sometimes identified by an alternate title, The Bloody Brother.

Rollo is a Viking leader, a powerful Danish duke at loggerheads with the king of Denmark, who then dies and leaves his two sons, Gurim and Rollo, leaving Rollo to be expelled and Gurim killed.

With his followers (known as Normans or northmen), Rollo invades the area of northern France, and besieges Paris. From the moonlit terrace of the royal palace, King Charles III gazes on the Princess Gisella, who is feasting with her father Rollo and his men. The voice of his brother, count of Lorraine, echoes from a deep cistern, where he is imprisoned by the king, who fears him. Gisella demands the head of the King's brother in a silver ewer, ignoring Charles' desperate alternatives, war with the Normans or with his own feudal vassals. The terrified king finally gives in. After a tense pause, the arm of the executioner rises from the cistern, offering the head to Rollo.

Concluding the Treaty of Saint-Clair-sur-Epte Rollo pledges feudal allegiance to the king and converts to Christianity. At the city gates, victory is celebrated in parade and dance, a ceremony observed by the King and Gisella. Gisella delivers a speech in praise of dancing. The Viking army plans to launch an invasion of England.

The plot is based loosely on the historical Rollo of Normandy and the foundation of the Duchy of Normandy.