A (general) dodecahedron is a polyhedron having 12 faces. Examples include the Bilinski dodecahedron, decagonal prism, elongated square dipyramid (Johnson solid ), hexagonal dipyramid, metabidiminished icosahedron (), pentagonal antiprism, pentagonal cupola (), regular dodecahedron, rhombic dodecahedron, snub disphenoid (), trapezo-rhombic dodecahedron, triakis tetrahedron, and undecagonal pyramid.

Crystals of pyrite () resemble slightly distorted dodecahedra (Steinhaus 1999, pp. 207-208), and sphalerite (ZnS) crystals are irregular dodecahedra bounded by congruent deltoids (Steinhaus 1999, pp. 207 and 209). The hexagonal scalenohedron is another irregular dodecahedron.

The regular dodecahedron, often simply called "the" dodecahedron, is the Platonic solid composed of 20 polyhedron vertices, 30 polyhedron edges, and 12 pentagonal faces, . It is also uniform polyhedron and Wenninger model . It is given by the Schläfli symbol and the Wythoff symbol .