宇宙距离尺度（cosmic distance ladder；亦作银河系外距离尺度，Extragalactic Distance Scale）是天文学家决定天体距离的一系列方法。要对一个天体进行真正「直接」的距离测量，只有在天体与地球之间够近的情况下才能做到（距离为1000秒差距）。测量距离更遥远天体距离的技术是奠基在各种已经用近距离天体测量法校正过其相关性的方法。这几种方法依赖标准烛光，这是一些光度已知的天体。

出现阶梯的模拟是因为没有一种方法或技术可以测量天文学的范围所遇到的所有距离尺度。相反的，一种方法可以用来测量近距离天体的距离，另一种方法可以测量邻近的中等距离天体，依此类推。每个阶梯的梯级提供的信息，可以用来确定更高的下一个阶梯的梯级。

The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are "close enough" (within about a thousand parsecs) to Earth. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.