Woyzeck (German pronunciation: [ˈvɔʏtsɛk]) is a stage play written by Georg Büchner. Büchner wrote the play between July and October 1836, yet left it incomplete at his death in February 1837. The play first appeared in 1877 in a heavily edited version by Karl Emil Franzos, and was first performed at the Residence Theatre in Munich on 8 November 1913.

Since then, Woyzeck has become one of the most influential and most often-performed German plays. Due to its unfinished nature, the play has inspired many diverging adaptations.

Büchner probably began writing the play between June and September 1836. It is loosely based on the true story of Johann Christian Woyzeck, a Leipzig wigmaker who later became a soldier. In 1821, Woyzeck, in a fit of jealousy, murdered Christiane Woost, a 46-year-old widow with whom he had been living; he was later publicly beheaded. Büchner's work remained in a fragmentary state at the time of his early death in 1837.

The play was first made public in a heavily edited and augmented version by Karl Emil Franzos, who published it in periodicals in 1875 and 1877, before including it in his edition of Büchner's collected works in 1879. Franzos mistakenly understood the title character's name in the manuscripts as "Wozzeck"; the play bore that title in its first stage productions, and in subsequent published editions based on Franzos' version. The play was not performed until November 8, 1913 at the Residenztheater, Munich, where it was produced by Max Reinhardt.

Not only did Franzos have to cope with Büchner's "microscopically small" handwriting, but the pages had faded so badly that they had to be chemically treated to make the text decipherable at all. Franzos was unaware of the real-life basis of the drama. The play was first generally disseminated in 1921 through the appearance of a new edition, edited by Georg Witkowski, which introduced the corrected title Woyzeck.

Franz Woyzeck, a lonely soldier stationed in a provincial German town, is living with Marie, the mother of his child who is not blessed by the church as the child was born out of wedlock. Woyzeck earns extra money for his family by performing menial jobs for the Captain and agreeing to take part in medical experiments conducted by the Doctor. At one of these experiments, the Doctor tells Woyzeck that he must eat nothing but peas. Woyzeck's mental health is breaking down and he begins to experience a series of apocalyptic visions. Meanwhile, Marie grows tired of Woyzeck and turns her attentions to a handsome drum major who, in an ambiguous scene taking place in Marie's bedroom, sleeps with her.

With his jealous suspicions growing, Woyzeck confronts the drum major, who beats Woyzeck up and humiliates him. Finally, Woyzeck stabs Marie to death by a pond. While a third act trial is claimed by some, notably A. H. J. Knight and Fritz Bergemann, to have been part of the original conception (what may be the beginning of a courtroom scene survives), the fragment, as left by Büchner, ends with Woyzeck disposing of the knife in the pond while trying to clean himself of the blood.

Here Franzos inserted the stage direction "ertrinkt" (he drowns), and although this emendation according to Knight "almost amounts to a forgery", most versions employ drowning as an appropriate resolution to the story.