Games like Sandbox Skyline
Games like Sandbox Skyline include Cities: Skylines, Cities: Skylines II, Banished, Foundation, and Planet Zoo. We matched them by the tags players give Sandbox Skyline on Steam (City Builder, Sandbox, Physics, Simulation, and Relaxing): closest matches first, and among equally close ones the better-known games.

Cities: Skylines
Shared: City Builder · Simulation · Sandbox

Cities: Skylines II
Shared: City Builder · Sandbox · Simulation

Banished
Shared: City Builder · Simulation · Sandbox

Foundation
Shared: City Builder · Simulation · Sandbox

Planet Zoo
Shared: Simulation · Sandbox · City Builder

Kingdoms and Castles
Shared: City Builder · Simulation · Resource Management

Prison Architect
Shared: Sandbox · Simulation · Building

Garry's Mod
Shared: Sandbox · Physics · Building

Manor Lords
Shared: City Builder · Simulation · Sandbox

Timberborn
Shared: City Builder · Sandbox · Building

Space Engineers
Shared: Sandbox · Simulation · Physics

Jurassic World Evolution
Shared: Simulation · Sandbox · Building

Frostpunk
Shared: City Builder · Resource Management · Survival

Against the Storm
Shared: City Builder · Simulation · Building

Planet Coaster
Shared: Simulation · Sandbox · Building

Dorfromantik
Shared: City Builder · Relaxing · Sandbox

Townscaper
Shared: Sandbox · City Builder · Relaxing

People Playground
Shared: Sandbox · Physics · Simulation

The Universim
Shared: City Builder · Sandbox · Building

Dwarf Fortress
Shared: City Builder · Simulation · Sandbox

Jurassic World Evolution 2
Shared: Sandbox · Simulation · Building

Planet Coaster 2
Shared: Sandbox · Simulation · City Builder

Oxygen Not Included
Shared: Resource Management · Sandbox · Building

Stardew Valley
Shared: Relaxing · Simulation · Sandbox