Liliaceae is the genetic family of Lily. Plants in this family have linear leaves, mostly with parallel veins, and flower parts in threes. Many plants in the Liliaceae are important ornamental plants, widely grown for their attractive flowers. Many plants in the family are poisonous if eaten. 

The genus Calochortus, which includes the Sego and Mariposa lilies, and its allied genera are separated into a separate family Calochortaceae in some schemes, while others maintain them as a subfamily of Liliaceae, the Calochortoideae.