Ur-Hamlet was the name given by nineteenth century German scholars to a pre-Shakespearean Hamlet written before 1589.

In that year Thomas Nashe implies the existence of such a play in his introduction to Robert Greene's Menaphon:

English Seneca read by Candle-light yeelds many good sentences, as Blood is a begger, and so forth; and if you intreate him faire in a frostie morning, hee will affoord you whole Hamlets, I should say handfuls of Tragicall speeches.

There is a record of a performance of Hamlet in 1594 in Philip Henslowe's diary and in 1596 Thomas Lodge wrote of "the ghost which cried so miserably at the theatre, like an oyster-wife, Hamlet, revenge!".

Because Nashe apparently makes allusions to Thomas Kyd in the same passage, and because of similarities between the Shakespearean Hamlet and Kyd's Spanish Tragedy, it is generally accepted that Kyd was the author. More controversial is the question of how much of Thomas Kyd's play survives in William Shakespeare's version, especially the first quarto of 1603.

Some anti-Stratfordians claim that there was no Ur-Hamlet, and that the references are merely signs that the Shakespearean Hamlet was written earlier than the generally accepted date. Only a few orthodox Shakespeareans, like Harold Bloom and Peter Alexander, have believed that Shakespeare himself was the author.