二进制的乘法器（英语：multiplier）是数字电路的一种组件，它可以将两个二进制数相乘。乘法器是由更基本的加法器组成的。

可以使用一系列计算机算数技术来实现数字乘法器。大多数的技术涉及了对部分积（partial product）的计算（其过程和我们使用竖式手工计算多位十进制数乘法十分类似），然后将这些部分积相加起来。这一过程与小学生进行多位十进制数乘法的过程类似，不过在这里根据二进制的情况进行了修改。

A binary multiplier is an electronic circuit used in digital electronics, such as a computer, to multiply two binary numbers. It is built using binary adders.

A variety of computer arithmetic techniques can be used to implement a digital multiplier. Most techniques involve computing a set of partial products, and then summing the partial products together. This process is similar to the method taught to primary schoolchildren for conducting long multiplication on base-10 integers, but has been modified here for application to a base-2 (binary) numeral system.