Cladida is a major subgroup of crinoids with a complicated taxonomic history.

Cladida was originally applied to a wide assortment of extinct crinoids with a dicyclic calyx.

Under this original definition, cladids would represent a paraphyletic order ancestral to several other major crinoid groups, particularly the living Articulata.

More recently, Cladida has been redefined as a monophyletic parvclass of pentacrinoids which encompasses articulates and the extinct Flexibilia (flexibles).

Cladids also include various minor taxa such as the hybocrinids and "cyathocrines".