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