数学上，超极限是几何的构造法，对一个度量空间串行X_n指定一个度量空间为其极限。超极限推广了度量空间的格罗莫夫－豪斯多夫收敛。

在自然数集上的超滤子ω，是一个有限可加的集合函数（可视为有限可加测度），从自然数集的幂集映射到集合{0,1}上，使得。一个在上的超滤子ω 称为非主要的，若对所有有限子集， 都有ω(F)=0。

For the direct limit of a sequence of ultrapowers, see Ultraproduct.

In mathematics, an ultralimit is a geometric construction that assigns to a sequence of metric spaces X_n a limiting metric space. The notion of an ultralimit captures the limiting behavior of finite configurations in the spaces X_n and uses an ultrafilter to avoid the process of repeatedly passing to subsequences to ensure convergence. An ultralimit is a generalization of the notion of Gromov-Hausdorff convergence of metric spaces.