Gerbert de Montreuil was a 13th-century French poet from the north of France.
He wrote Le Roman de la violette or Gérard de Nevers, one of the most outstanding medieval poems, famous for its vivid narrative and faithful depiction of contemporary customs. The poem underwent countless adaptations and imitations. It tells the trials of the unfortunate and innocent Euriant, who becomes an object of public dispute between Gérard de Nevers and Lisiard de Forez, the former taking her defense while the other suggests she is guilty of misconduct by claiming he knows of a violet-shaped mark on her bosom. The story percolated into Shakespeare's Cymbeline via Giovanni Boccaccio, and Carl Maria von Weber's opera Euryanthe.