Games like Fallout Shelter
Games like Fallout Shelter include Oxygen Not Included, Once Human, Factorio, RimWorld, and This War of Mine. We matched them by the tags players give Fallout Shelter on Steam (Free to Play, Base Building, Survival, Post-apocalyptic, and Singleplayer): closest matches first, and among equally close ones the better-known games.

Oxygen Not Included
Shared: Base Building · Survival · Singleplayer

Once Human
Shared: Free to Play · Survival · Base Building

Factorio
Shared: Base Building · Survival · Strategy

RimWorld
Shared: Base Building · Survival · Management

This War of Mine
Shared: Survival · Singleplayer · Base Building

Frostpunk
Shared: Survival · Post-apocalyptic · Base Building

Sheltered
Shared: Base Building · Survival · Post-apocalyptic

Kenshi
Shared: Survival · Post-apocalyptic · Simulation

Prison Architect
Shared: Base Building · Simulation · Management

Raft
Shared: Survival · Base Building · Building

7 Days to Die
Shared: Survival · Base Building · Post-apocalyptic

Scrap Mechanic
Shared: Survival · Base Building · Building

Medieval Dynasty
Shared: Survival · Base Building · Building

Infection Free Zone
Shared: Base Building · Post-apocalyptic · Survival

Terraria
Shared: Survival · 2D · Building

Project Zomboid
Shared: Survival · Post-apocalyptic · Simulation

ARK: Survival Evolved
Shared: Survival · Base Building · Building

Endzone - A World Apart
Shared: Survival · Post-apocalyptic · Base Building

Frostpunk 2
Shared: Survival · Post-apocalyptic · Strategy

Manor Lords
Shared: Base Building · Strategy · Simulation

Sons Of The Forest
Shared: Survival · Base Building · Building

Enshrouded
Shared: Base Building · Survival · Crafting

ARK: Survival Ascended
Shared: Survival · Base Building · Building

Cities: Skylines
Shared: Simulation · Management · Singleplayer