King Leir is an anonymous Elizabethan play about the life of the ancient Brythonic king Leir of Britain. It was published in 1605 but was entered into the Stationers' Register on 15 May 1594. The play has attracted critical attention principally for its relationship with King Lear, Shakespeare's version of the same story.
The records of theatre impresario Philip Henslowe show that King Leir was performed on 6 and 8 April 1594 at the Rose Theatre, by a cast that combined personnel from two acting companies, Queen Elizabeth's Men and Sussex's Men. Other records claim that the play was often acted, though these two are the only specific performances known. It has been suggested that Shakespeare, who was a player in the Queen's company of the 1590s, may have actually performed in King Leir.
The moste famous Chronicle historye of Leire king of England and his Three Daughters was entered into the Stationers' Register on 14 May 1594, by stationer Adam Islip; but Islip's name is crossed out of the record and the name of fellow stationer Edward White is substituted. Perhaps this conflict between stationers prevented the play's publication in 1594; certainly it did not appear in print until the next decade. It was registered again on 8 May 1605 (as the Tragecall historie of kinge Leir and his Three Daughters &c), by stationer Simon Stafford. The first edition appeared later that year, printed by Stafford for the bookseller John Wright, with the title The true Chronicle History of King Leir and his three daughters, Gonorill, Ragan and Cordella. The title page states that the drama "hath been diverse and sundry times lately acted". The 1605 quarto was the sole edition of the play during the seventeenth century.
There is no consensus of scholarly opinion on the authorship of King Leir. The play has been variously attributed to Thomas Kyd, Robert Greene, George Peele, Thomas Lodge, Anthony Munday, and Shakespeare himself.