重力红移或称重力红位移指的是光波或者其他波动从重力场源（如巨大星体或黑洞）远离时，整体频谱会往红色端方向偏移，亦即发生「频率变低，波长增长」的现象。

重力红移的程度常标记为变量z：

其中是极远处观测者所测量到的光子波长；是重力源如星球，其上的光源发出时所测量到的光子波长。

重力红移的现象可以从广义相对论预测：

其中

In astrophysics, gravitational redshift or Einstein shift is the process by which electromagnetic radiation originating from a source that is in a gravitational field is reduced in frequency, or redshifted, when observed in a region of a weaker gravitational field. This is a direct result of gravitational time dilation - as one moves away from a source of gravitational field, the rate at which time passes is increased relative to the case when one is near the source. As frequency is inverse of time (specifically, time required for completing one wave oscillation), frequency of the electromagnetic radiation is reduced in an area of a lower gravitational field (i.e., a higher gravitational potential). There is a corresponding reduction in energy when electromagnetic radiation is red-shifted, as given by Planck's relation, due to the electromagnetic radiation propagating in opposition to the gravitational gradient. There also exists a corresponding blueshift when electromagnetic radiation propagates from an area of a weaker gravitational field to an area of a stronger gravitational field.