The Roman Gods are a race of immortal higher beings who control the forces of nature and human endeavors. The majority of them are descendents from the first generation of Titans, their ancestors and chief enemies. There a currently twleve major gods, the Olympians, who rule over the earth, all of whom are under the rule of Jupiter (or his Greek form Zeus), god of the sky and oaths. There are many other minor gods and goddesses who serve smaller but necessary purposes in the world. Despite, their immense power, they are subject to divne laws, and, in theory, cannot break oaths sworn upon the river styx.
- Although the word "god" can be gender-neutral and applied to either female or male, the gender adapted terms for a male would be known as "god", whereas a female would be called a "goddess".
- Throughout the Heroes of Olympus series, there have been mentions of other gods, besides the Greco-Roman, that are strongly implied to exist.
- In The Lost Hero, Piper's grandfather mentions about Cherokee divine beings.
- In The Son of Neptune, Frank's grandmother mentions Chinese Gods and Dragons.
- In The House of Hades, Leo believes that the Abrahamic God created the Earth as he states that every machine needs a creator.
- Interestingly, in The Son of Neptune, after Percy take a ride with an Inuit Indian (who also tells Inuit myths and gods), Percy starts to believe that other gods beyond Greeks-Romans might possibly exist, but given that his life is already quite complicated, he prefers to not think much about it.
- Gods do not have DNA, as they are beings of magic and power. Due to this, romantic relationships between children of 2 different gods (e.g Ares and Apollo) aren't ever incestuous.