加性高斯白噪声（英语：Additive white Gaussian noise，AWGN）在通信领域中指的是一种功率谱函数是常数（即白噪声），且幅度服从高斯分布的噪声信号。因其可加性、幅度服从高斯分布且为白噪声的一种而得名。

该噪声信号为一种便于分析的理想噪声信号，实际的噪声信号往往只在某一频段内可以用高斯白噪声的特性来进行近似处理。由于AWGN信号易于分析、近似，因此在信号处理领域，对信号处理系统（如滤波器、低噪音高频放大器、无线信号传输等）的噪声性能的简单分析(如：信噪比分析)中，一般可假设系统所产生的噪音或受到的噪音信号干扰在某频段或限制条件之下是高斯白噪声。

Additive white Gaussian noise (AWGN) is a basic noise model used in Information theory to mimic the effect of many random processes that occur in nature. The modifiers denote specific characteristics:

Wideband noise comes from many natural sources, such as the thermal vibrations of atoms in conductors (referred to as thermal noise or Johnson-Nyquist noise), shot noise, black body radiation from the earth and other warm objects, and from celestial sources such as the Sun. The central limit theorem of probability theory indicates that the summation of many random processes will tend to have distribution called Gaussian or Normal.