在讯号处理中，过采样（英语：Oversampling）是指以远远高于信号带宽两倍或其最高频率对其进行取样的过程。过采样可以帮助避免混叠、改善分辨率以及降低噪音。

In signal processing, oversampling is the process of sampling a signal with a sampling frequency significantly higher than the Nyquist rate. Theoretically a bandwidth-limited signal can be perfectly reconstructed if sampled above the Nyquist rate, which is twice the highest frequency in the signal. Oversampling improves resolution, reduces noise and helps avoid aliasing and phase distortion by relaxing anti-aliasing filter performance requirements.