壬烷是化学式为CH₃(CH₂)₇CH₃的烷烃。由壬烷衍生出的取代基称为“壬基”，相应的环烷烃则为环壬烷。壬烷有35个异构体。

• 烷烃

Nonane is a linear alkane hydrocarbon with the chemical formula C₉H₂₀. It is a colorless, flammable liquid, occurring primarily in the component of the petroleum distillate fraction commonly called kerosene, which is used as a heating, tractor, and jet fuel. Nonane is also used as a solvent, distillation chaser, fuel additive, and a component in biodegradable detergents.