算术逻辑单元（英语：Arithmetic Logic Unit, ALU）是中央处理器的执行单元，是所有中央处理器的核心组成部分，由及闸和或闸构成的算数逻辑单元，主要功能是进行二进位的算术运算，如加减乘(不包括整数除法)。基本上，在所有现代CPU体系结构中，二进制都以二补数的形式来表示。

An arithmetic logic unit (ALU) is a digital electronic circuit that performs arithmetic and bitwise logical operations on integer binary numbers. This is in contrast to a floating-point unit (FPU), which operates on floating point numbers. An ALU is a fundamental building block of many types of computing circuits, including the central processing unit (CPU) of computers, FPUs, and graphics processing units (GPUs). A single CPU, FPU or GPU may contain multiple ALUs.