Full list of all 80 Dishonored achievements worth 1,640 gamerscore. It takes around 25-30 hours to unlock all of the achievements in the base game on Xbox 360.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 3 DLC packs containing 30 achievements worth 640 Gamerscore.
You killed characters with each weapon and offensive gadget
You completed all missions after the prologue, alerting or killing no one but key targets
You completed all missions after the prologue without alerting anyone
You finished the game without purchasing any supernatural powers or enhancements, besides Blink
You made others kill 5 of their own allies
You killed 5 characters with Drop Assassination
You completed the game without killing anyone
You caused 5 unintentional suicides
You killed 4 enemies in less than 1 second using the crossbow
You killed 6 enemies in less than 1 second
You collected all the Sokolov paintings
After Coldridge Prison, you eluded 5 pursuers at once without killing them or leaving the map
You completed the game in high chaos
You killed Morgan Pendleton with steam
You grabbed a live grenade and threw it back, killing an attacker
You completed the game in low chaos
You completed the game
You saved Empress Emily Kaldwin
You deactivated at least 5 security systems on Kingsparrow Island
You played from the first mission through Kaldwin's Bridge killing fewer than 10 characters
You stayed in possession of others for most of a 3 minute period
You traveled 30 meters in less than 1 second
You acquired 15 equipment upgrades
You collected 10 bone charms
You fought 5 enemies at once and none of them survived
You located Lady Emily Kaldwin, heir to the throne
You abducted Anton Sokolov, Royal Physician
You assassinated the Lord Regent, Hiram Burrows
You brought about the Lord Regent's fall from grace by broadcasting his crimes
You recovered your belongings
You completed all the Granny Rags side missions
You completed all the Slackjaw side missions
You got the Art Dealer's safe combination for Slackjaw, but robbed the safe first
You completed the Boyle Estate mission without spoiling the party
You reached the top of Kaldwin's Bridge
You spared Daud’s life
You neutralized all key targets using indirect means
You killed a tallboy using only your sword
You killed an enemy with the Wall of Light
You assassinated an assassin
You used a rat tunnel
You took possession of a fish
You assassinated 10 unaware enemies
After escaping prison, you completed a mission, not alerting anyone and killing less than 5 people
After escaping Coldridge Prison, you completed a mission without alerting anyone
You protected Callista's uncle, Captain Geoff Curnow
You eliminated High Overseer Campbell
You escaped Coldridge Prison
You escaped prison and navigated the sewers undetected
You pickpocketed items worth a total of 200 coins
You finished Mystery Foe without using any active supernatural powers
Find Emily's doll hidden in each of the 10 challenges
Complete all Normal and Expert challenges with a 3-Stars rating
Get to Wave 13 in Back Alley Brawl killing all combatants personally
Complete Train Runner before the train arrives at the station
Find all of the collectable figurines in Burglar on Expert
Perform a drop assassination of at least 150 meters in the Kill Cascade challenge
Complete Assassin's Run with 100% accuracy using only head shots
In Bonfires, perform all the special combination jumps in 1 round
Finish Chain Kill or Bend Time Massacre without failing any wave, including bonuses
You got the information you needed from the Rothwild Slaughterhouse
Meet with Thalia Timsh, the Barrister's Niece
Purchase all of the Favors in The Knife of Dunwall
Complete The Knife of Dunwall in High Chaos
Complete The Knife of Dunwall in Low Chaos
Complete The Knife of Dunwall without alerting anyone
Complete The Knife of Dunwall without killing anyone
Attach an arc mine to a rat, resulting in a kill
Perform a drop assassination from atop the Empress statue in The Knife of Dunwall
Speak with the statue of Delilah Copperspoon in Timsh's estate
Deliver (or attempt) the killing blow on Corvo
Break Lizzy Stride out of Coldridge Prison
Restore the Undine to working condition
Purchase at least 8 favors in The Brigmore Witches
Complete The Brigmore Witches in High Chaos
Complete The Brigmore Witches in Low Chaos
Complete The Brigmore Witches without alerting anyone
Complete The Brigmore Witches without killing anyone
Survive The Brigmore Witches in low chaos with 10,000 coins
Use an enemy lifted with Pull as a shield