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.
Scored an epic 5,000,000 or more in a Challenge Map
Finished the game in 15 hours or more
Completed all collectible sets
Discovered all secret areas
Completed 25 optional Thieving Objectives
Completed all Client Jobs in The City
Completed all Basso Jobs in The City
Completed a collectible set
Picked 100 pockets in a single playthrough
Used 40,000 gold
Disarmed ten trap mechanisms
Killed or knocked out 10 people using the environment
Discovered 15 secret areas
Completed 10 optional Thieving Objectives
Picked a pocket and a lock using the focus ability
Stole all loot and collectibles in a single chapter.
Uncovered Lyegrove's secret
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
Finished Chapter Eight
Reached the final chapter without using the focus ability
Finished Chapter Seven
Finished Chapter Six
Shot a bottle in mid-air with an arrow
Finished Chapter Five
Found all the secret stashes in Moira
Stole 5 collectibles
Finished Chapter Four
Finished Chapter Three
Sweet sixteen. Snuff said.
Finished 3 consecutive chapters without taking damage
Finished Chapter Two
Finished a single chapter without alerting anyone
Finished Chapter One
Finished the Prologue
Picked a lock with masterful speed