Didacticism is a philosophy that emphasizes instructional and informative qualities in literature and other types of art. The term has its origin in the Ancient Greek word διδακτικός (didaktikos), "related to education and teaching", and signified learning in a fascinating and intriguing manner.

Didactic art was meant both to entertain and to instruct. Didactic plays, for instance, were intended to convey a moral theme or other rich truth to the audience. An example of didactic writing is Alexander Pope's An Essay on Criticism (1711), which offers a range of advice about critics and criticism. An example of didactism in music is the chant Ut queant laxis, which was used by Guido of Arezzo to teach solfege syllables.

Around the 19th century the term didactic came to also be used as a criticism for work that appears to be overly burdened with instructive, factual, or otherwise educational information, to the detriment of the enjoyment of the reader (a meaning that was quite foreign to Greek thought). Edgar Allan Poe even called didacticism the worst of "heresies" in his essay The Poetic Principle.