At least Set, Osiris, Mithra and some others that I can't recall right now are in WOD. I didn't read those manuals in at least 15 years... I don't remember any Greek one in canon but it might be just my memory, anyway they would fit in. It's up to the "storyteller" to keep things "believable enough", as long as there is not an inflaction of gods and crazy stuff around and as long as the plot is coherent it should be ok.
Mithra-Persia Fire Cult Methuselah
Set- Evil Evil Evil Eunic Antediluvian Possibly 2nd Gen along with his Brother Osiris
Osiris- Mummy-Vampire-Spector-Vampire Cult Leader Antediluvian Possibly 2nd Gen along with his Brother Osiris
Artemis- Methuselah bad ass
Odin- Methuselah from, you guessed it Norway
Neferu-Handmaiden of Set 4th gen
Kemintiri- Minor Goddess of Death, Red List Setite 4th gen through her own hand (reputedly on her brother-real life)
Lazarus - Christian figure 4th gen Cappadocian
Original Mahatma- 4th Gen Cappadocian
Miclántecuhtli -Aztec Blood God 4th generation Gangrel who may in fact be 3rd Generation through Diablerie.
Meneleus -4th Generation Greek Hero of Troy who was absent during it's sacking (Brujah)
Helena (of Troy) said to be divine of Aphrodite 4th generation, betrayed Troy, betrayed most places she touched (Toreador)
The Morrigan- Goddess of War, Death and Ravens- Celtic, Brujah 4th Generation.
Shit you not- The Scorpion King- General of Set's Army. Lost in battle with the Ventrue Menes who united Egypt's N. and S. Kingdoms.
The Dionysain-yep Bacchus the god of wine party and debauchery. Malkavian 4th generation.
The Niktuku are all monster gods- Baba Yaga, Azazael, Abraxes, Nuklevee. Note that all of these might have been or are 3rd generation as it is possible Absimiliard might have been 2nd generation by the time he sired them. All other Nosferatu are descendent through what would have been another Niktuku but somehow evaded the blood bond Medusa is the mother of all other Nosferatu in modern nights or so the myth goes. One thing that contradicts this is Trajan another Methuselah is generally credited with the Net, which led to the Shreknet.
Minos- the Minos of Greek Legend. Sire of the infamous Helena, he was diablerized a mere 13 years after her embrace. She is a vengeful lass.
Mi-Ka-Il a Persian God and 4th generation Toreador along Antonas (Ventrue 4th gen) and The Dracon (4th gen favored childe of Tzimisce) so all Methuselahs, all hugely powerful and capable of near miracles with their powers, founded and ruled Constantinople until it's fall, often posed as the Holy Trinity, Ma-Ri, a long lost love returned after the fall to console her former lover and had assumed the name Mary the Black, served as his Persian Consort and fellow Goddess in ancient times. She is Bali, so I guess you know how this ends..... she snacked him down, deservedly so.
Tiamat- an entire book can be written on her exploits. She at first seems quite evil, but in the current times, her sacrifice is all that has prevented death on a scale unprecedented. She accepted the help of a demon DragonSky and forged a sword named the Sword of Null, and did many bad bad things in the past. Once she got control back, she held it and now holds the demon within herself to prevent more harm. Yeah she is a goddess. 4th or possibly 3rd generation. Committed Diablerie numerous times back with 5th generation was high.
Veddartha- Reputedly the Ventrue Antediluvian in some texts, more likely the childe that with the help of True Brujah and Set, killed and Diablerized Ventrue. Also worshiped as a god for many years. Now believed to be 3rd or 4th or 5th generation, listed as Mithras's sire. His history is pretty intense. He is a current member of the Icconu...
Dracul, Dracula, Tzimisce supergods. Yup, the modern ideal of the vampire. Sad compelling saga.
The Tremere Inner Council, which never assembles together anymore thus negating the stupidity of the 5th edition premise that they and the Tremere Salout Antediluvian were killed, were all sorcerers well into their hundreds if not thousands of years old when the Christian invasion, started to destroy the old magic. You know the rest of the story. They used a 4th generation Tzimisce to become 4th generation Tremere in a ritual, and then gobbled up dozens of 4-7th generation Gangrel and Nosferatu to make their Gargoyle super weapons. While not gods, they were certainly influential throughout history.
There are more, but looking through all these books is distracting me..... more to come maybe...