Crown molding, also known as ceiling molding, is a decorative strip used to conceal an area where a wall meets the ceiling. Crown molding flares out to a finished edge, and fits snugly into the intersection of wall and ceiling by a right angle. Crown molding is usually constructed of wood, plaster, vinyl or metal. This type of molding is used on both the interior and exterior, and can also be used to cap window and door hoods, cornices, pilasters, and cabinets.

The family of classic crown molding styles is large. Four core styles are as follows:

Cavetto is a simple symmetrical molding style, consisting of a concave surface that juts out at the top.

Cyma Recta crown molding is bulging and convex where it meets the wall, and reverses to a concave form where it meets the ceiling.

Ovolo crown molding has a quarter elliptical profile, with two beveled edges running along the top and bottom.

Torus molding is convex and semi-circular, with two beveled edges running along the top and bottom. Torus molding differs from standard molding in that it does not fit into the intersection of wall and ceiling. Instead, Torus molding attaches to the wall alone.

The classic crown molding styles can be thought of as a base for ornate decorative patterns and designs. Decorative wood moldings are commonly carved, whereas decorative plaster moldings are produced by the induction of liquid plaster into a re-usable mold where it dries in the shape of the mold.