Here is the full list of all 116 Settlements achievements.
Successfully defend against a settlement attack
Complete Animal Slayer deed
Kill 500 enemy
Have a Character with the Combat Medic Skill
Reach The Era: Late Bronze Age
Obtain an adventure chest
Obtain a Rank 10 Character Skill
Have 30 or more Settled Familes
Obtain a pet
Have 25 or more Settled Familes
Kill 50 Enemies with a Single Character
Have 20 or more Settled Familes
Have a Character with 30+ Armour Value
Have a Character with 15 Skills
Have a Character with the Leadership Skill
Founded Settlement 5
Purchase 3 Feats with a Single Character
Have 15 or more Settled Familes
Founded Settlement 4
Complete an Adventure Quest
Kill 25 Enemies with a Single Character
Reach The Era: Early Bronze Age
Have 10 or more Settled Familes
Obtain a Rank 5 Character Skill
Complete 10 Tasks
Founded Settlement 3
Kill 10 Enemies with a Single Character
Purchase a Feat
Read a Skillbook
Have 5 or more Settled Familes
Kill 1 Enemy
Founded Settlement 2
Your First Family
Founded Settlement 6
Founded Settlement 7
Founded Settlement 8
Founded Settlement 9
Founded Settlement 10
Kill 100 Enemies with a Single Character
Reach The Era: Iron Age
Reach The Era: Steel Age
Reach The Era: Gunpowder Age
Reach The Era: Industrial Age
Reach The Era: Electric Age
Reach The Era: Computer Age
Reach The Era: Space Age
Create an automated Machine
Build a Factory
Have 40 or more Settled Familes
Have 50 or more Settled Familes
Have 60 or more Settled Familes
Victory Ending 1
Victory Ending 2
Victory Ending 3
Doom Clock at 25+
Doom Clock at 50+
Doom Clock at 75+
Have a Character with 50+ Armour Value
Have a Character with 70+ Armour Value
Kill 250 Enemies with a Single Character
Kill 500 Enemies with a Single Character
Build a War Machine
Build the Science Lab
Complete Vineling Slayer deed
Complete Undead Slayer deed
Complete Human Slayer deed
Complete Beast Slayer deed
Complete Elemental Slayer deed
Complete Arachnid Slayer deed
Complete Avian Slayer deed
Collect all of King Rat's Special Treasure
Collect all of Wolf Man's Special Treasure
Collect all of Razor's Special Treasure
Collect all of The Spawn Pool's Special Treasure
Collect all of The Nest's Special Treasure
Collect all of The Headhunter Brothers' Special Treasure
Collect all of Whiteout's Special Treasure
Collect the Wasp Drone Pet!
Complete 30 Tasks
Complete 60 Tasks
Destroy the Sandman Base
Kill 1000 Enemies with a Single Character
Use the Missile Defence System in Combat
Have a level 10 World Skill
Have 5 level 10 World Skills
Have 10 level 10 World Skills
Beat the game on Gentle Difficulty or Higher
Beat the game on Easy Difficulty or Higher
Beat the game on Standard Difficulty or Higher
Beat the game on Hard Difficulty or Higher
Beat the game on Challenging Difficulty
Collect all of The Swamp Vampire's Special Treasure
Successfully defend against 10 settlement attacks
Successfully defend against 20 settlement attacks
Kill 2500 enemy
Kill 5000 enemy
Kill 10000 enemy
Obtain 10 pets
Obtain 50 pets
Breed a pet
Breed a rare pet
Go into battle with 8 frontline pets
Defeat a rare boss spawn
Obtain 10 adventure chests
Obtain 50 adventure chests
Obtain all of the Deep Wilds chests
Defeat 5 rare boss spawns
Defeat the rare boss: The White Wolf
Defeat the rare boss: Dire Straights
Defeat the rare boss: The Thrasher
Defeat the rare boss: Advanced Force
Defeat the rare boss: The Wall
Defeat the rare boss: Dark Hunter
Collect all of The Rubble's Special Treasure
Collect all of Father Frost's Special Treasure
Collect all of Toxicity's Special Treasure