在微分几何中，类似度量张量，里奇张量也是一个在黎曼流形每点的切空间上的对称双线性形式。以格雷戈里奥·里奇-库尔巴斯托罗（Gregorio Ricci-Curbastro）为名的里奇张量或里奇曲率张量（Ricci curvature tensor）。提供了一个数据去描述给定的黎曼度规(Riemannian metric)所决定的体积究竟偏离寻常欧几里得 n- 空间多少的程度。粗略地讲，里奇张量是用来描述「体积扭曲」的一个值；也就是说，它指出了n-维流形中给定区域之n-维体积，其和欧几里得n-空间中与其相当之区域的体积差异程度。更精确的描述请见下文「直接的几何意义」段落。

In differential geometry, the Ricci curvature tensor, named after Gregorio Ricci-Curbastro, represents the amount by which the volume of a geodesic ball in a curved Riemannian manifold deviates from that of the standard ball in Euclidean space. As such, it provides one way of measuring the degree to which the geometry determined by a given Riemannian metric might differ from that of ordinary Euclidean n-space. The Ricci tensor is defined on any pseudo-Riemannian manifold, as a trace of the Riemann curvature tensor. Like the metric itself, the Ricci tensor is a symmetric bilinear form on the tangent space of the manifold (Besse 1987, p. 43).