基本电荷，，是一个质子所带的电荷，或一个电子所带的负电荷的量。它是一个基本物理常数，是原子单位和一些其它自然单位制中的电荷单位。

根据国际科学技术数据委员会所公布e的值，基本电荷的值大约为

在高斯单位制中，它的值为

自从1909年罗伯特·密立根的油滴实验中测量出基本电荷后，人们便认为它不可再分了。1960年发现了夸克，它们的电荷为⁄₃ e和⁄₃ e，所以把“基本电荷”用来指电子的电荷便不完全正确了；然而单独的夸克至今没有探测到，都是两个以上的夸克聚集在一起，使得总电荷为基本电荷的整数倍。

The elementary charge, usually denoted as e or sometimes q, is the electric charge carried by a single proton, or equivalently, the magnitude of the electric charge carried by a single electron, which has charge −e. This elementary charge is a fundamental physical constant. To avoid confusion over its sign, e is sometimes called the elementary positive charge. This charge has a measured value of approximately 6981160217662079999♠1.6021766208(98)×10coulombs. In the cgs system, e is 6990480320425000000♠4.80320425(10)×10 statcoulombs.