An Humorous Day's Mirth is an Elizabethan era stage play, a comedy by George Chapman, first acted in 1597 and published in 1599.
Algernon Charles Swinburne called Chapman's play All Fools one of the finest comedies in English. "The plot is intricate and ingenious and shows that Chapman had been taking lessons of Jonson's masters, Plautus and Terence."
An Humorous Day's Mirth was performed by the Admiral's Men at the Rose Theatre; it has been identified with the "Humours" play that the company acted on 1 May 1597, as described in a contemporary letter by Dudley Carleton. A 1598 inventory of the Admiral's properties lists items of clothing in the costumes of specific characters in the play.
The 1599 quarto, the only edition of the play in the seventeenth century, was printed and published by Valentine Simmes, who is generally recognized as one of the best London printers of his generation; Simmes printed nine Shakespeare quartos in the 1597–1604 period. The quality of Simmes's work is evident in the Chapman volume: "A shop proofreader was especially careful in correcting the first quarto edition...."
Yet if the printer did a good job of printing his text, the text he had to work with possessed significant deficiencies. "The text...is so corrupt, and the stage directions are so infrequent and confusing, that it is extremely difficult to follow the story." The play was probably "altered and published without the author's supervision." It is worth noting that in the first edition of a later Chapman comedy, All Fools (1605), the dedication indicates that Chapman oversaw the printing of that play, to prevent a version "patch'd with others' wit" from reaching the public. This has been taken to indicate that the printed versions of Chapman's earliest plays, The Blind Beggar of Alexandria and Humorous Day's Mirth, were corrupted and adulterated by other hands.