Since there seems to be some controversy about this one, I'll give you a list of what each planet is name for, grouped first by origin and second by orbital order, which ought to tell you which planets are and are not named for Roman or Greek mythology:
Roman:
Greek:
Hawaiian:
Native American:
Rapa Nui:
The planet Mercury is named after the Roman messenger god (the counterpart of the Greek Hermes).
The planet Neptune was named for the Roman god of water and the seas.In the original Greek language, from whence this Roman god was taken, his name was Poisedon.
The planet Neptune is named after the Roman god Neptune, the god of the sea. Neptune is the Roman equivalent of the Greek god Poseidon.
There is a Greek and a Roman god named Apollo. There is no planet named after Apollo, unless you know of the Apollo planet that no one knows about yet.
Saturn was named after the Roman god of agriculture
The planet Jupiter is named after the roman god Jupiter, the roman counterpart of the greek god Zeus.
The planet Mercury is named after the Roman messenger god (the counterpart of the Greek Hermes).
The planet Neptune was named for the Roman god of water and the seas.In the original Greek language, from whence this Roman god was taken, his name was Poisedon.
The planet Neptune is named after the Roman god Neptune, the god of the sea. Neptune is the Roman equivalent of the Greek god Poseidon.
There is no planet named after the Greek god of war.There is however a planet named after the Roman god of war, which is Mars.The Greek god of war is Ares. He does not currently have a planet named after him.
Saturn is the planet that is named after the roman god of agriculture and Cornus (Zeus's father) is the Greek god
There is a Greek and a Roman god named Apollo. There is no planet named after Apollo, unless you know of the Apollo planet that no one knows about yet.
Mercury is named for the Roman god, the Roman equivalent of the Greek god Hermes.
Saturn was named after the Roman god of agriculture
the planet Jupiter named after the roman god in roman mythology
There is a small planet named Ceres, the Roman version of Demeter.
The dwarf planet, Pluto, was named for the Greek God of the underworld.