In geometry, the biaugmented pentagonal prism is one of the Johnson solids (J₅₃). As the name suggests, it can be constructed by doubly augmenting a pentagonal prism by attaching square pyramids (J₁) to two of its nonadjacent equatorial faces. (The solid obtained by attaching pyramids to adjacent equatorial faces is not convex, and thus not a Johnson solid.)

Biaugmented pentagonal prism
Type	Johnson J52 – J53 – J54
Faces	8 equilateral triangles 3 squares 2 pentagons
Edges	23
Vertices	12
Vertex configuration	2(42.5) 2(34) 2x4(32.4.5)
Symmetry group	C2v
Dual polyhedron	parabilaterotruncated pentagonal bipyramid
Properties	convex
Net

A Johnson solid is one of 92 strictly convex polyhedra that is composed of regular polygon faces but are not uniform polyhedra (that is, they are not Platonic solids, Archimedean solids, prisms, or antiprisms). They were named by Norman Johnson, who first listed these polyhedra in 1966.^[1]