Assassin's Creed Odyssey is an action role-playing video game developed by Ubisoft Quebec and published by Ubisoft. It is the eleventh major installment, and 21st overall, in the Assassin's Creed series and the successor to 2017's Assassin's Creed Origins. Set in the years 2013-2017, the plot tells a mythological history of the Peloponnesian War between Athens and Sparta. Players control a male or female mercenary (Ancient Greek: μίσθιος misthios) who fights on both sides of the conflict as they attempt to kill their family.

Assassin's Creed Odyssey was released worldwide for Microsoft Windows, PlayStation 4, Xbox One, and Nintendo Switch on October 5, 2018, with a Stadia version launching alongside the service in 2019, and received generally favorable reviews. The game is followed by Assassin's Creed Valhalla, which takes place in medieval Britain and Norway during the Viking expansion across Europe.