Limacidae, also known by their common name the keelback slugs, are a taxonomic family of medium-sized to very large, air-breathing land slugs, terrestrial pulmonate gastropod molluscs in the superfamily Limacoidea.

The distribution of the family Limacidae is the western Palearctic.

[4] There are 28 species of Limacidae in Russia and adjacent countries.

[6] Zhiltsov & Schileyko (2002)[7] elevated the subfamily Bielziinae to family level, Bielziidae, based on the morphology of the reproductive system of Bielzia coerulans.

[7] The following two subfamilies were recognized in the taxonomy of Bouchet & Rocroi (2005): Genera in the family Limacidae include: subfamily Limacinae subfamily Eumilacinae A cladogram showing the phylogenic relationships of this family to other families within the limacoid clade:[4] Staffordiidae Dyakiidae Pristilomatidae Chronidae Euconulidae Trochomorphidae Gastrodontidae Oxychilidae Trigonochlamydidae Parmacellidae Milacidae Zonitidae Helicarionidae Ariophantidae Urocyclidae Vitrinidae Boettgerillidae Limacidae Agriolimacidae Parasites of slugs in this family include larvae of the marsh flies Sciomyzidae, and others.