山脉是相连的山体的统称。

一般由于板块相互挤压使得地壳隆起，形成山脉，这类山脉称为褶皱山脉。例如：喜马拉雅山脉是由于亚欧板块受印度板块的冲撞而形成的；从库页岛、日本、**到菲律宾群岛的彩带列屿是由亚欧板块与太平洋板块的推挤形成的。

一般是一个高６０００ｍ才算是山脉。

由火山作用所形成的通常是独立的山峰，但在某些情况下，一连串的火山活动也会形成山脉，例如夏威夷群岛，即是火山群山脉。

山脉依高度可分为三种类型：

A mountain range (also mountain barrier, belt, or system) is a geographic area containing numerous geologically related mountains. A mountain system or system of mountain ranges, sometimes is used to combine several geological features that are geographically (regionally) related. On Earth, most significant mountain ranges are the result of plate tectonics, though mountain ranges are formed by a range of processes, are found on many planetary mass objects in the Solar System and are likely a feature of most terrestrial planets.