An altar and reredos from University Church, Dublin

A reredos is a screen or decoration behind the altar in a church, usually depicting religious iconography or images. It can be made of stone, wood, metal, ivory, or a combination of materials. The images may be painted, carved, gilded, composed of mosaics, and/or embedded with niches for statues. Sometimes a tapestry is used, or other fabric such as silk or velvet.

The term dates back to the 14th and 15th centuries, but was nearly obsolete until revived in the 19th century.

See also: altarpiece.