Great dodecicosahedron
Type	Uniform star polyhedron
Elements	F = 32, E = 120 V = 60 (χ = −28)
Faces by sides	20{6}+12{10/3}
Coxeter diagram	(with extra double-covered triangles) (with extra double-covered pentagons)
Wythoff symbol	3 5/3 (3/2 5/2) |
Symmetry group	Ih, [5,3], *532
Index references	U63, C79, W101
Dual polyhedron	Great dodecicosacron
Vertex figure	6.10/3.6/5.10/7
Bowers acronym	Giddy

In geometry, the great dodecicosahedron (or great dodekicosahedron) is a nonconvex uniform polyhedron, indexed as U₆₃. It has 32 faces (20 hexagons and 12 decagrams), 120 edges, and 60 vertices.^[1] Its vertex figure is a crossed quadrilateral.

It has a composite Wythoff symbol, 3 5⁄3 (3⁄2 5⁄2) |, requiring two different Schwarz triangles to generate it: (3 5⁄3 3⁄2) and (3 5⁄3 5⁄2). (3 5⁄3 3⁄2 | represents the great dodecicosahedron with an extra 12 {10⁄2} pentagons, and 3 5⁄3 5⁄2 | represents it with an extra 20 {6⁄2} triangles.)^[2]

Its vertex figure 6.10⁄3.6⁄5.10⁄7 is also ambiguous, having two clockwise and two counterclockwise faces around each vertex.