While not exactly Greek (they are far older than any known civilization), they have inspired Greek and sometimes Roman myths. They are sometimes called the Olympian Gods.
Most of the Milky Way galaxy, which they call the Olympian Galaxy, is ruled by Zeus and his family.
Rule over the rest of the local universe is shared with his brothers Poseidon (who rules the Aegian Galaxy) and Hades (who rules the Stygian Galaxy, also called the Underworld).
It is the youngest and most chaotic pantheon.

 

Known gods

Adrestia
Aphrodite
Apollo
Ares
Artemis
Athena
Circe
Deimos
Dike
Dionysus
Enyo
Eris
Gaea
Hades
Hebe
Hekate
Helios
Hephaestus
Hera
Hermes
Ilithyia
Kronos
Nike
Nyx
Persephone
Phobos
Poseidon
Rhea
Selene
Tartarus
Themis
Tyche
Vesta
Zeus