Magnoliidae
Magnoliidae is a botanical subclass name; it may refer to:

Magnoliids, a major group of basal angiosperms.
Magnoliidae sensu Chase & Reveal, a botanical subclass consisting of all angiosperms.
 In the Dahlgren and Thorne systems, a group consisting of the Dicotyledons (Class Magnoliopsida in the Cronquist system)