罗伯逊-沃尔克度规（英语：Robertson-Walker metric）是H.P.罗伯逊和沃尔克分别于1935年和1936年证明的。由于俄国数学家弗里德曼和比利时物理学家勒梅特也作出了重要的贡献，因此也称作弗里德曼-罗伯逊-沃尔克度规（英语：Friedmann-Robertson-Walker metric，缩写为FRW度规）或者弗里德曼-勒梅特-罗伯逊-沃尔克度规（英语：Friedmann-Lemaître-Robertson-Walker metric，缩写为FLRW度规）。

按照宇宙学原理，在宇宙学尺度上天体系统最终要的特征之一是均匀性和各向同性。H.P.罗伯逊和沃尔克分别于1935年和1936年证明，适用于上述均匀性和各向同性要求的四维时空只有3种，它们的时空度规具有下列形式：

The Friedmann–Lemaître–Robertson–Walker (FLRW) metric is an exact solution of Einstein's field equations of general relativity; it describes a homogeneous, isotropic expanding or contracting universe that is path connected, but not necessarily simply connected. The general form of the metric follows from the geometric properties of homogeneity and isotropy; Einstein's field equations are only needed to derive the scale factor of the universe as a function of time. Depending on geographical or historical preferences, a subset of the four scientists — Alexander Friedmann, Georges Lemaître, Howard P. Robertson and Arthur Geoffrey Walker — may be named (e.g., Friedmann–Robertson–Walker (FRW) or Robertson–Walker (RW) or Friedmann–Lemaître (FL)). This model is sometimes called the Standard Model of modern cosmology. It was developed independently by the named authors in the 1920s and 1930s.