Caustic Ramblings

Let's first get the etymological information out of the way:

Jupiter or Iuppiter is a vocative compound derived from the archaic Latin Iovis and pater (Latin for father). Linguistic studies identify the Latin theonym Jupiter as having derived from the phonologically similar proto-Indo-European compound *dyēus- pəter-, which refers to the "Father God," ruler of the daytime sky. This is the very same deity from whom also derives the Sanskrit Dyaus or Dyaus Pita ("Sky Father") of the Vedas, the Germanic *Tiwaz, and of course the Greek Zeus. This word *dyēus- pəter- itself derives from the proto-Indo-European root diu, meaning “bright” or "to shine," referring to the light of the sun and sky in daytime. For the Romans, as well as other mythological systems derived from proto-Indo-European roots such as that of the Vedas and the Norse, the god of the sky was also the supreme god. Thus, the similarity between Jupiter's Latin title and those given to the celestial gods in the Sanskrit, Germanic and Greek languages provides strong linguistic evidence that the god had a connection to the Proto-Indo-European sky god.

Jupiter's alternative title Jove, meanwhile, is an English formation based on Iov-, the stem of oblique cases of the Latin name for the Vedic Dyaus Pita.

It does seem that both Odin and Zeus played a very similar "All-fatherly" role in each respective mythology. But they certainly were not the same figure, not did they represent the same exact archetypal attributes. Zeus/Jupiter was depicted as a grand-regal sky god, whereas Odin was more portrayed as a wizardly god of knowledge.

And then there's the difference in planetary associations. At some point in time, the Greeks and Romans had retrofitted their pantheons into the Babylonian astrotheology schema, thus giving a planetary association to the most major of their deities. For example, Zeus/Jupiter became associated with the literal object in the sky we now all Jupiter, Aphrodite/Venus with the planet Venus, ect. So when the Romans met other peoples (usually by conquest), they would associate the foreign gods with their own by trying to match them up to their own sort of planetary associations. When the Romans made contact with the Germanic peoples, they associated Wotan/Odin with their own Mercury, probably as a snap judgement based on vague observations of shared attributes. However, as far as I know, the Germanic peoples had no such system of associating their gods with specific celestial objects, so to say that "Odin in Mercury" could very much be a gross misrepresentation of that god.

At the end of the day, we can say that Wotan/Odin is a father god and was head of the Norse pantheon (I'm unsure about other Germanic tribes though), but lacked the sky and thunder/lightning attributes of Zeus. In the Germanic system that latter quality was assigned to Thor. So we could say that Zeus is kind of a combination of Odin and Thor. But we can't just correlate two similar gods from different pantheons and say they're both just two different names for the same figure/entity.

Finally, within occult circles we find the idea that Odin is an actual entity somewhere out there in the cosmos; an entity people can learn to communicate with. I won't comment on the potential veracity of such a claim. Anyone reading this can search around on their own for stories and anecdotes that shine more light on this topic.