钙质海绵纲是多孔动物门的一个纲。多产于浅海。种类很多。体型大多小于10cm。单体的，例如：毛壶（Grantia）；分枝成群体的，例如白枝海绵（Leucosolenia）。钙质骨针(CaCO₃ spicules)有针状体、三辐体等等。

在地层中的出现晚于寻常海绵和六放海绵。

The calcareous sponges of class Calcarea are members of the animal phylum Porifera, the cellular sponges. They are characterized by spicules made out of calcium carbonate in the form of calcite or aragonite. While the spicules in most species have three points, in some species they have either two or four points.