Seguenziidae is a family of very small deepwater sea snails, marine gastropod mollusks in the superfamily Seguenzioidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).
Species from this family occur in the Atlantic Ocean, the Pacific Ocean, the Indian Ocean and the Antarctic Ocean, mostly at bathyal and abyssal depths. Only a few species have been found at depths less than 300 m and none at intertidal depths.
The thin, translucent, white shell has a trochiform shape. They are small or very small. Their maximum height is 22 mm. They are usually nacreous. The inner lip has often a tooth-like fold. The outer lip has characteristically one to three concave notches (except in the genus Guttula). The chitinous operculum is multispiral. The rhipidoglossan radula has intermediate characteristics of the former order Archaeogastropoda (by having more than two pairs of marginal teeth) and the former order Mesogastropoda (by having a single pair of lateral teeth).
This family consists of four following subfamilies (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005) with the following genera 
- Genera brought into synonymy
Fluxiella Okutani, 1968: synonym of Fluxinella B.A. Marshall, 1983
Seguenziella Marshall, 1983: synonym of Quinnia Marshall, 1988
- Seguenza, G. 1876: Studii stratigrafici sulla formazione pliocenica dell'ltalia Meridionale. Bollettino del Regio Comitato Geologico d'Italia 5 & 6: 179-189
- Goryachev, W. N. (1979): On the system of deep-sea molluscan family Seguenziidae. P. 70-71 in: Likharev, I. M. ed., Molluscs: main results of their study - abstracts of communications. U.S.S.R Academy of Sciences Zoological Institute, sixth meeting on the investigation of molluscs. Nauka
- Bandel, K. (1979): The nacreous layer in the shells of the gastropod family Seguenziidae and its taxonomic significance. Biomineralisation 10 : 49 - 61
- Quinn J.F. (1983). A revision of the Seguenziacea Verrill, 1884 (Gastropoda : Prosobranchia). I. Summary and evaluation of the superfamily. Proceedings of the Biological Society of Washington, 96(4):725-757
- Marshall B.A. (1991). Mollusca Gastropoda : Seguenziidae from New Caledonia and the Loyalty Islands. In A. Crosnier & P. Bouchet (Eds) Résultats des campagnes Musorstom, vol. 7. Mémoires du Muséum National d'Histoire Naturelle, A, 150:41-109