How many gods and goddesses are in greek mythology?

There are many Greek gods and goddesses when you include the minor ones. But there were twelve main gods in Greek mythology know as the Olympians. They are:

1.Zeus
2.Poseidon
3.Hades
4.Hera
5.Demeter
6.Athena
7.Hermes
8.Apollo
9.Artemis
10.Ares
11.Aphrodite
12.Hephaestus

Some people will say that Dionysus (the god of wine) is also a major god instead of Hephaestus, but technically they are both major gods. Hestia can also be considered a major god, but she rarely is since in Greek mythology she gave up her throne for Dionysus.