In ancient Greek religion and mythology, Euphrosyne (/juːˈfrɒzɪniː/; Ancient Greek: Εὐφροσύνη, romanized: Euphrosúnē) is a goddess, one of the three Charites. She was sometimes named Euthymia (Ancient Greek: Εὐθυμία, lit. 'good mood') or Eutychia (Ancient Greek: Εὐτυχία, lit. 'good luck').

According to Hesiod, Euphrosyne and her sisters Thalia and Aglaea are the daughters of Zeus and the Oceanid nymph Eurynome. Alternative parentage may be Zeus and Eurydome, Eurymedousa, or Euanthe; Dionysus and Coronis; or Helios and the Naiad Aegle.

The Roman author Hyginus, in his Fabulae, also mentions a figure named Euphrosyne, who is the daughter of Nox (Night) and Erebus (Darkness).

Euphrosyne is a goddess of good cheer, joy and mirth. Her name is the female version of the word euphrosynos, "merriment". Pindar wrote that these goddesses were created to fill the world with pleasant moments and good will. The Charites attended the goddess of beauty Aphrodite.

In art, Euphrosyne is usually depicted with her sisters dancing.

Euphrosyne and her sisters' main cult was located in Athens, Sparta, or Boetia.