Fascia (/ˈfeɪʃə/) is an architectural term for a vertical frieze or band under a roof edge, or which forms the outer surface of a cornice, visible to an observer.^[1]

Typically consisting of a wooden board, unplasticized PVC (uPVC), or non-corrosive sheet metal, many of the non-domestic fascias made of stone form an ornately carved or pieced together cornice, in which case the term fascia is rarely used.

The word fascia derives from Latin fascia meaning "band, bandage, ribbon, swathe". The term is also used, although less commonly, for other such band-like surfaces like a wide, flat trim strip around a doorway, different and separate from the wall surface.

The horizontal "fascia board" which caps the end of rafters outside a building may be used to hold the rain gutter. The finished surface below the fascia and rafters is called the soffit or eave.

In classical architecture, the fascia is the plain, wide band (or bands) that make up the architrave section of the entablature, directly above the columns. The guttae or drip edge was mounted on the fascia in the Doric order, below the triglyph. The term fascia can also refer to the flat strip below the cymatium.