Games like New Fief
Games like New Fief include Cities: Skylines, Prison Architect, Oxygen Not Included, Cities: Skylines II, and SimAirport. We matched them by the tags players give New Fief on Steam (Casual, City Builder, Building, Base Building, and Singleplayer): closest matches first, and among equally close ones the better-known games.

Cities: Skylines
Shared: City Builder · Building · Management

Prison Architect
Shared: Building · Base Building · City Builder

Oxygen Not Included
Shared: Base Building · Building · Singleplayer

Cities: Skylines II
Shared: City Builder · Building · Singleplayer

SimAirport
Shared: City Builder · Casual · Management

Gas Station Simulator
Shared: Casual · Building · Singleplayer

Project Highrise
Shared: Building · Management · Singleplayer

Manor Lords
Shared: City Builder · Base Building · Building

Frostpunk
Shared: City Builder · Building · Base Building

Factorio
Shared: Base Building · Building · Management

SimCity™ 4 Deluxe Edition
Shared: City Builder · Building · Base Building

Dyson Sphere Program
Shared: Building · Base Building · City Builder

Against the Storm
Shared: City Builder · Base Building · Building

Ratopia
Shared: Building · Base Building · City Builder

RimWorld
Shared: Base Building · Management · Singleplayer

Planet Zoo
Shared: Building · Management · City Builder

Two Point Hospital
Shared: Building · Management · Singleplayer

Jurassic World Evolution 2
Shared: Building · Management · City Builder

Jurassic World Evolution
Shared: Building · Management · City Builder

Stacklands
Shared: City Builder · Management · Building

Workers & Resources: Soviet Republic
Shared: City Builder · Base Building · Building

Hearth and Hamlet
Shared: City Builder · Casual · Base Building

Kingdom Two Crowns
Shared: City Builder · Building · Base Building

shapez
Shared: Base Building · Singleplayer · Building