A side show is an extra secondary production associated with a circus. Its proper name is a "Ten in One" referring to the practice of having a revolving show of Ten acts under a single tent.

Sideshows had a hierarchy of performers in terms of prestige with "Born Freaks" at the top followed by "Made Freaks" such as tattooed men and women and "Working Acts" such as sword swallowers and fire eaters. Contrary to contemporary perceptions many of the "Born Freaks" were not looked down upon and many were in fact the owners and operators of the shows.

Today only one "Ten in One" remains active in the World, The Sideshow by the Seashore sponsored by Coney Island USA in Brooklyn, NY.

The anthropoligist Jim Rose runs a modern side show called Jim Rose Circus.

There are actually several sideshows working in the U.S. today (Ses Carny, Carnival Diablo, Brothers Grimm and many more), consisting mainly of 'working acts' and 'made freaks' as well as the classic curiosity displays. The sideshow is alive and well, slowly growing back into its former greatness.