Here is the full list of all 37 Thief achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Finished the game with a custom difficulty of 700 points or more
Discovered all secret areas
Scored an epic 5,000,000 or more in a Challenge Map
Completed all collectible sets
Finished the game without a single kill or knockout
Finished the game in 15 hours or more
Reached the final chapter without using the focus ability
Completed all Basso Jobs in The City
Shot a bottle in mid-air with an arrow
Completed 25 optional Thieving Objectives
Completed all client jobs in The City
Used 40,000 gold
Completed a collectible set
Found all the secret stashes in Moira
Disarmed ten trap mechanisms
Picked 100 pockets in a single playthrough
Killed or knocked out 10 people using the environment
Discovered 15 secret areas
Finished the game on Master difficulty
Finished Chapter Eight
Picked a pocket and a lock using the focus ability
Finished Chapter Seven
Finished Chapter Six
Finished Chapter Five
Finished Chapter Four
Finished Chapter Three
Completed 10 optional Thieving Objectives
Finished 3 consecutive chapters without taking damage
Finished Chapter Two
Picked a lock with masterful speed
Sweet sixteen. Snuff said.
Stole all loot and collectibles in a single chapter.
Stole 5 collectibles
Finished a single chapter without alerting anyone
Finished Chapter One
Uncovered Lyegrove's secret
Finished the Prologue