In geometryGeometry (Greek γεωμετρία; geo = earth, metria = measure) is a part of mathematics concerned with questions of size, shape, and relative position of figures and with properties of space. Geometry is one of the oldest sciences. Initially a body of practical knowledge concerning lengths, areas, and volumes, in the third century B.C. geometry was put into an axiomatic form by Euclid, whose treatment set a standard for many centuries to follow. Astronomy served ...geometry, the hexagonal prism is a prismNo quick definition available. prism with hexagonalNo quick definition available. hexagonal base.

It is an octahedronAn octahedron (plural: octahedra) is a polyhedron with eight faces. A regular octahedron is a Platonic solid composed of eight equilateral triangles, four of which meet at each vertex. The octahedron's symmetry group is Oh, of order 48. This group's subgroups include ...octahedron. However, the term octahedron is mainly used with "regular" in front or implied, hence not meaning a hexagonal prism; in the general meaning the term octahedron it is not much used because there are different types which have not much in common except having the same number of faces.

If faces are all regular, the hexagonal prism is a semiregular polyhedronA semiregular polyhedron is a polyhedron with regular faces and a symmetry group which is transitive on its vertices. Or at least, that is what follows from Thorold Gosset's 1900 definition of the more general semiregular polytope.Thorold Gosset On the Regular and Semi-Regular Figures in Space of n Dimensions, Messenger ...semiregular polyhedron. This is the fourth in an infinite set of prisms formed by square sides and two regular polygon caps.

As in most prisms, the volume is found by taking the area of the base, with a side length of , and multiplying it by the height .