Genre (French for 'kind, sort') is any style or form of communication in any mode (written, spoken, digital, artistic, etc.) with socially agreed-upon conventions developed over time. In popular usage, it normally describes a category of literature, music, or other forms of art or entertainment, based on some set of stylistic criteria, as in literary genres, film genres, music genres, comics genres, etc. Often, works fit into multiple genres by way of borrowing and recombining these conventions. Stand-alone texts, works, or pieces of communication may have individual styles, but genres are amalgams of these texts based on agreed-upon or socially inferred conventions. Some genres may have rigid, strictly adhered-to guidelines, while others may show great flexibility. The proper use of a specific genre is important for a successful transfer of information (media-adequacy).

Critical discussion of genre perhaps began with a classification system for ancient Greek literature, as set out in Aristotle's Poetics. For Aristotle, poetry (odes, epics, etc.), prose, and performance each had specific features that supported appropriate content of each genre. Speech patterns for comedy would not be appropriate for tragedy, for example, and even actors were restricted to their genre under the assumption that a type of person could tell one type of story best. The academic discipline about genres is called genre studies (or genre theory).

Genres proliferate and develop beyond Aristotle's classifications— in response to changes in audiences and creators. Genre has become a dynamic tool to help the public make sense out of unpredictability through artistic expression. Given that art is often a response to a social state, in that people write, paint, sing, dance, and otherwise produce art about what they know about, the use of genre as a tool must be able to adapt to changing meanings.

Among non-Western approaches, the five-category Cinematic Taxonomy proposed by Alireza Kaveh distinguishes genre from adjacent concepts such as style, format, medium, and tradition.

The term genre is often used in the history and criticism of visual art, but in art history has meanings that overlap rather confusingly. Genre painting is a term for paintings where the main subject features human figures to whom no specific identity attaches – in other words, figures are not portraits, characters from a story, or allegorical personifications. They usually deal with subjects drawn from "everyday life". These are distinguished from staffage: incidental figures in what is primarily a landscape or architectural painting. "Genre" is also be used to refer to specialized types of art such as still-life, landscapes, marine paintings and animal paintings, or groups of artworks with other particular features in terms of subject-matter, style or iconography.

The concept of the "hierarchy of genres" was a powerful one in artistic theory, especially between the 17th and 19th centuries. It was strongest in France, where it was associated with the Académie royale de peinture et de sculpture which held a central role in academic art. The genres, which were mainly applied to painting, in hierarchical order are:

The hierarchy was based on a distinction between art that made an intellectual effort to "render visible the universal essence of things" (imitare in Italian) and that which merely consisted of "mechanical copying of particular appearances" (ritrarre). Idealism was privileged over realism in line with Renaissance Neo-Platonist philosophy.

A literary genre is a category of literary composition. Genres may be determined by literary technique, tone, content, or even (as in the case of fiction) length. Genre should not be confused with age category, by which literature may be classified as either adult, young adult, or children's. They also must not be confused with format, such as graphic novel or picture book. The distinctions between genres and categories are flexible and loosely defined, often with subgroups.