The Florian theory of Shakespeare authorship investigates the influential role that John Florio’s writing style and works played on Shakespeare’s oeuvre, and his possible role as collaborator and editor of the plays which were publicly attributed to William Shakespeare.

The Florian theory of Shakespeare authorship does not hold that Shakespeare was an illiterate, third-rate play actor, but an entrepreneur and writer who had a fundamental role in the production and in the writing of the plays, and that his collaboration with John Florio gave birth to the works which were later attributed solely to the Stratford man due to Florio’s foreign origins.

Various explanations are offered for this theory: most commonly that John Florio had the knowledge of Italian authors, culture and language that can be frequently found in Shakespeare’s plays. John Florio and Shakespeare shared the same patrons and friends. They both faced criticism and attacks from the same enemies: Thomas Nashe and Robert Greene. Playwright Ben Jonson, Florio’s friend, hailed him as “Ayde of his Muses”. Moreover, John Florio was also the first translator in English of Montaigne’s Essays, which has been frequently mentioned as major source for Shakespeare’s plays, before and after Florio’s translation. John Florio, like Shakespeare, contributed to create more than one thousand new words for the English language, many of which, with compounds and proverbs, are frequently and erroneously attributed to Shakespeare. John Florio has also been proposed as main editor of the First Folio.