Eftychia
Eutychia, phonetically transliterated as Eftychia (; ) is a Greek female given name, meaning "happiness". It is derived from the Greek words εὖ (good) and τύχη (luck). The diminutive Effie is a pet form of Eftychia.

Notable people with the given name include:
 Eftychia Karagianni (born 1973), Greek water polo player and Olympic medalist
 Eftychia Papavasilopoulou (born 1981), Greek-American diver
 Effy Vayena (born 1972), Greek and Swiss bioethicist

Greek feminine given names
Feminine given names