正十二面体烷（Dodecahedrane），也称十二面烷、正十二面烷，是一个正十二面体形状的碳氢化合物，化学式为C₂₀H₂₀，不存在于自然界中。它的合成首先由俄亥俄州立大学的Leo Paquette于1982年完成，该合成路线被誉为有机合成的经典作品之一。

正十二面体烷 中，每个顶点碳与三个邻近的碳原子相连，碳-碳键角为正五边形的内角108°，与sp杂化碳原子的109.5°相近，因此张力不大。每个碳上连有一个氢原子，整个分子为I_h对称性（类似于富勒烯），质子核磁共振谱中氢原子只有一个单峰，化学位移为3.38pm。

Dodecahedrane is a chemical compound (C₂₀H₂₀) first synthesised by Leo Paquette of Ohio State University in 1982, primarily for the "aesthetically pleasing symmetry of the dodecahedral framework".

In this molecule, each vertex is a carbon atom that bonds to three neighbouring carbon atoms. The 108° angle of each regular pentagon is close to the ideal bond angle of 109.5° for an sp hybridised atom. Each carbon atom is bonded to a hydrogen atom as well. The molecule, like fullerene, has I_h symmetry, evidenced by its proton NMR spectrum in which all hydrogen atoms appear at a single chemical shift of 3.38 ppm. Dodecahedrane is one of the Platonic hydrocarbons, the others being cubane and tetrahedrane, and does not occur in nature.