Sabellaria alcocki [2][3][4] is a species of bristle worm described by Charles Joseph Gravier in 1906[5] and named in honour of Alfred William Alcock.

Sabellaria spinulosa and S. alcocki are smaller than S. alveolata and inhabit the subtidal and lower intertidal/sublittoral fringes.

Sabellaria spinulosa has been described from the North Sea (Leuckart 1849) and S. alcocki from the Indian Ocean (Gravier 1906).

[6] Sabellaria alcocki is included in the genus Sabellaria and family Sabellariidae.

[2][7] No subspecies are listed in Catalogue of Life.