{{Tassobox
|colore=pink
|nome=Eleutherozoa
|statocons=
|immagine=250px
|didascalia=
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|dominio=Eukaryota
|regno=Animalia
|sottoregno=Eumetazoa Bilateria
|superphylum=Deuterostomia
|phylum=Echinodermata
|subphylum='''Eleutherozoa'''<br/><small>Bather, 1900</small>
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'''Eleutherozoa''' e' un subphylum di ''echinodermi''; si tratta di animali marini ricoperti da piastre calcaree con processi spinosi.

== Superclassi ==
*Asterozoa <small>Zittel, 1895</small>
*Cryptosyringida <small>Smith, 1984</small>

== Collegamenti esterni ==
*|06/05/2008}}

{{Taxobox
| name = Eleutherozoa
| image = Ochre sea star on beach, Olympic National Park USA.jpg
| image_caption = ''Pisaster ochraceaus''
| regnum = Animalia
| phylum = Echinodermata
| subphylum = '''Eleutherozoa'''
| subphylum_authority = Bather, 1900
| subdivision_ranks = Superclasses
| subdivision =
* Superclass/Clade Asterozoa
** Order Asteroidea
** Order †Somasteroidea
* Superclass Echinozoa
** Order Echinoidea
** Order Holothuroidea
* ''Incertae sedis''
** Order Ophiuroidea
}}

'''Eleutherozoa''' is a subphylum of echinoderms. They are mobile animals with the mouth diceted towards the substrate. They usually have a madreporite, tube feet, and moveable spines of some sort, and some have Tiedemann's bodies on the ring canal. All living echinoderms except Crinoidea belong here.

==Systematics==
There are 2 main competing hypotheses about the internal subdivision, both about equally well supported by both molecular and morphological data. They differ in their placement of the Ophiuroidea (brittle stars), and are named accordingly.

The "Cryptosyringida" hypothesis posits that the "sea-star" morphology is basal eleutherozoans and echinoderms to be able to firmly decide for or against any of these hypotheses at present.<ref>Wray (1999)</ref>

The Asterozoa would have to be ranked as a superclass or treated as an unranked clade between the Cryptosyringida and the Eleutherozoa, depending on whether the "Asterozoa" or "Cryptosyringida" hypothesis turns eventually out to be correct.