In Assassin's Creed Odyssey, which ancient civilization is the game's primary setting?

In Assassin's Creed Odyssey, the primary setting is ancient Greece.

The game takes place during the Peloponnesian War in the fifth century BCE, a conflict between Athens and Sparta and their allies. Players explore a large version of the Greek world, including mainland regions and islands in the Aegean Sea. The setting supports naval travel, political missions, mercenary encounters, and stories involving figures from Greek history and mythology.

Odyssey was released in 2018 and is set several centuries before Assassin's Creed Origins. Its playable protagonist can be either Kassandra or Alexios, although the game's novelization treats Kassandra as the canonical protagonist. The player character is a descendant of Leonidas I of Sparta.

Ancient Rome and ancient Egypt are also important settings elsewhere in the franchise, which can cause confusion. Rome is especially prominent in Brotherhood, while Egypt is the setting of Origins. Odyssey is specifically associated with classical Greece and the Peloponnesian War.