A facade mosaic is an artwork or ornamental design composed by arranging several individual tiles, none of which bears any actual representation on itself (usually each tile or piece is a single color). It is similar to a mural except that the latter is painted while a mosaic is built from preformed pieces like a puzzle.

The tiles or pieces in a mosaic may be ceramic, glass, or less frequently stone or various man-made materials.

To be listed as a feature, a mosaic must cover a substantial portion of an object's surface. A small sign or house number applied as a mosaic is not sufficient.