'Mr. William Shakespeares Comedies, Histories, & Tragedies' is the 1623 published collection of William Shakespeare's plays. Modern scholars commonly refer to it as the First Folio.
Printed in folio format and containing 36 plays (see list of Shakespeare's plays), it was prepared by Shakespeare's colleagues John Heminges and Henry Condell. It was dedicated to the "incomparable pair of brethren" William Herbert, 3rd Earl of Pembroke and his brother Philip Herbert, Earl of Montgomery (later 4th Earl of Pembroke).
Although eighteen of Shakespeare's plays had been published in quarto prior to 1623, the First Folio is arguably the only reliable text for about twenty of the plays, and a valuable source text even for many of those previously published. The Folio includes all of the plays generally accepted to be Shakespeare's, with the exception of Pericles, Prince of Tyre, The Two Noble Kinsmen, and the two lost plays, Cardenio and Love's Labour's Won.