children's toy and scientific curiosity, usually consisting of a box with an eyehole, through which the viewer sees a miniature scene or stage setting, painted or constructed in perspective. Peep shows of an earlier time are often the only accurate representation of the stage design and scenery of the period.

The earliest known peep shows are the perspective views said to have been painted in transparent colours on glass and lighted from behind for various effects, from sunshine to moonlight, by Leon Battista Alberti (Alberti, Leon Battista) in 1437. Later models (some preserved in the Kunsthistorisches Museum in Vienna) have designs that are apparently patterned on Renaissance court masques and pageants, such as that of the discovery of Diana by Actaeon, with fully modelled figures set against a background painted in careful perspective.

In the 17th century, peep shows in their cabinets were often exhibited in the streets by itinerant showmen, and the device became a popular children's toy. Some, equipped with movable scenery and wooden or cardboard figures, developed into the juvenile theatres of the 19th century (see toy theatre). The peep show was also the precursor of many types of optical toys, including the stereoscope and the magic lantern.