Here is the full list of all 37 THIEF achievements worth 1,000 gamerscore. It takes around 40-50 hours to unlock all of the achievements on Xbox One.
Completed 25 optional Thieving Objectives
Discovered all secret areas
Scored an epic 5,000,000 or more in a Challenge Map
Killed or knocked out 10 people using the environment
Found all the secret stashes in Moira
Shot a bottle in mid-air with an arrow
Used 40,000 gold
Completed all collectible sets
Stole all loot and collectibles in a single chapter.
Completed 10 optional Thieving Objectives
Uncovered Lyegrove's secret
Picked a pocket and a lock using the focus ability
Finished the game with a custom difficulty of 700 points or more
Finished the game without a single kill or knockout
Finished the game on Master difficulty
Reached the final chapter without using the focus ability
Finished 3 consecutive chapters without taking damage
Finished a single chapter without alerting anyone
Finished Chapter Eight
Finished the game in 15 hours or more
Finished Chapter Seven
Picked 100 pockets in a single playthrough
Completed all Client Jobs in The City
Completed a collectible set
Completed all Basso Jobs in The City
Disarmed ten trap mechanisms
Discovered 15 secret areas
Finished Chapter Six
Finished Chapter Five
Finished Chapter Four
Finished Chapter Three
Picked a lock with masterful speed
Sweet sixteen. Snuff said.
Stole 5 collectibles
Finished Chapter Two
Finished Chapter One
Finished the Prologue