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