Lanassa was the name of some ancient noble women: the mythical ancestress of the royal dynasty of the Molossians in Epirus. According to some accounts, she is equated with Andromache. Lanassa (wife of Pyrrhus), a daughter of king Agathocles of Syracuse, wife of king Pyrrhus of Epirus and later of the diadoch Demetrius I of Macedon
Lanassa may also refer to: Lanassa (annelid), a genus of polychaetes in the family Terebellidae