Full list of all 93 Assassin's Creed Odyssey achievements. It takes around 80-100 hours to unlock all of the achievements in the base game on Windows.
The base game contains 50 achievements, and there are 5 DLC packs containing 43 achievements.
Complete Xenia's questline.
Complete the Hippokrates questline.
Complete Episode 9 + Epilogue.
Defeat all the Cultists of Kosmos.
Upgrade your Spear to Tier 6.
Complete Episode 8.
Complete Episode 7.
Complete the Olympic questline.
Outwit the Sphinx.
Discover Atlantis and speak with Pythagoras.
Recover the Cyclops's eye from a goat on Kephallonia.
Unveil all sub-regions of Greece.
Complete all underwater location objectives.
Complete the Daughters of Artemis questline.
Complete 20 Quests on Pephka, Obsidian and Abantis islands.
Defeat Medusa.
Complete Episode 6.
Upgrade the Adrestia to Legendary Status.
Complete Episode 5.
Reach Level 50.
Defeat the Cyclops.
Become Champion of the Arena.
Engrave your first item.
Engrave a Legendary Item with a Legendary Effect.
Equip 1 Legendary melee weapon and 5 Legendary armor pieces.
Become the first Mercenary.
Acquire a Tier 3 active Ability.
Complete Markos's questline.
Defeat the Minotaur.
Defeat a Mercenary in the Arena.
Defeat a full cluster of Cultists of Kosmos.
Equip a Legendary Armor set.
Kill the Leader of any Region with Low Resources, other than Megaris.
Perform an Overpower Attack with every weapon type.
Complete Episode 4.
Complete 20 Bounties, War Contracts, or Naval Quests from Message Boards.
Fully crew the Adrestia with Legendary Lieutenants.
Sink your first Epic Ship.
Cleave a ship while having an all-women crew.
Complete Episode 3.
Recruit and assign a Legendary NPC for your ship.
Win your first on land conquest battle in any region (excluding Megaris in Hero's Journey).
Complete Episode 2.
Spend the night with another character.
Raise your Bounty to the maximum level.
Acquire and equip your first Legendary item.
Upgrade the Adrestia for the first time.
Cleave a ship in half.
Complete Episode 1.
Complete the Battle of 300.
Acquire the Sword of Kings
Secure your bloodline
Kill all the Ancients in the Order of Dominion in Messenia
Heal by getting 10 headshot kills while you have the Golden Harbinger equipped.
Kill the Makedonian Lion
Heal by parrying 10 times with the Judgment of the Lion.
Continue the bloodline.
Kill all of the Ancients in the Order of the Storm in Achaia.
Set 10 enemy ships on fire.
Kill 10 enemies using the Fury of the Bloodline Ability.
Kill all the Ancients in the Order of the Hunters in Makedonia
Discover the truth about Darius' past
Land a Rush Assassinate that chains 4 times with the Blade of the Lion
Kill 10 enemies using the Rapid Fire ability.
Kill 10 enemies using the Death Veil ability
Complete Old Flames Burn Brighter
Complete One Really, Really Bad Day
Complete Every Story Has an Ending
Complete The Heir of Memories
Complete Divine Intervention.
Complete The Image of Faith
Complete The Show Must Go On.
Complete A Brother's Seduction
Complete The Daughters of Lalaia
Complete A Poet's Legacy.
Complete A Friend Worth Dying For
Defeat the Hekatonchires.
Forge the 3 Legendary Weapons.
Collect all the Keeper's Insights in Episode 3.
Completely fill the Knowledge Sequence.
Kill 10 Isu Soldiers with the Blessing of Kronos enhancement.
Dethrone the king.
Defeat all of the Fallen.
Collect all the Keeper's Insights in Episode 2.
Close all Tartaros Rifts.
Defeat Cerberos.
Win the conquest of Elysium with freed humans from the 3 main regions.
Remember who you are.
Collect all the Keeper's Insights in Episode 1.
Destroy all of the Marble Maiden Tributes.
Kill all Overseers in Elysium.
Defeat Arges, the Bright One
Defeat Steropes the Lightning Bringer.