A fan convention, or con, is an event in which fans of a particular TV show, comic book, or actor, or an entire style of entertainment such as science fiction or anime and manga, gather together to meet famous personalities (and each other) face-to-face. Some popular Fan run cons are Farpoint and Shore Leave in Baltimore, Philcon in Philadelphia, MediaWest Con in Michigan and many others. The fan run cons are held for the fans, by the fans.

At commercial shows which may be called "conventions", actors often give out free autographs to the fans, perhaps in exchange for a flat appearance fee, and sometimes may perform songs that have no relevance to the shows so as to entertain the fans.

Such conventions are usually quite expensive and are hosted in hotels. There is often tight security for the celebrities to protect against potentially fanatic fans. (Such features are not common at traditional science fiction conventions, which are more oriented towards science fiction as a mode of literature, rather than towards visual media, and do not include any paid appearances by famous personalities.)

Many conventions have award presentations relating to their genre (such as the Hugo Awards which have been presented at the World Science Fiction Convention since 1953).

Anime conventions, gaming cons, filk cons and furry fandom conventions may all be considered ultimately derivatives of science fiction conventions, which began in the late 1930s.

From anime conventions has arisen the widespread stereotype of the fans' tendency to dress up as their favorite characters (known as cosplay in anime terminology) in elaborate costumes that are time-consuming and/or expensive to assemble. (While the wearing of costumes, and even a costume competition [known in the United States as a "masquerade"] has been an occasional feature of traditional science fiction conventions since Forrest J. Ackerman wore one during the 1st World Science Fiction Convention in 1939, this has never been the dominant feature of such events.)