A guest, in the context of show business, refers to an outside performer – such as an actor, musician, or celebrity – who participates in an event, recording, concert, or show, but does not belong to the regular cast, band, or performing group. They may be referred to as a guest artist in a musical context, or a guest star when it concerns performance art, the latter term often being used to denote the appearance of a celebrity. Some production companies recognize these appearances with credits such as “special guest star” or “special musical guest star”.

A guest character is a role in a fictional entertainment setting, typically involved only once or a few times in the plot, which distinguishes them from main characters, supporting characters, and recurring characters due to their limited appearances.

In pop music, phrases like “featuring”, “with”, or “and” often describe guest appearances and are commonly abbreviated to “Feat.”, “Ft.”, “f/”, “f.” in credit lists. In television series, a guest star usually refers to an actor who appears for one or a few episodes. Meanwhile, in radio and television shows, a guest star typically implies a celebrity guest on the show. Thus, a ‘guest’ denotes a non-regular participant contributing a unique element to the performance, event, or show.