Games like Victoria 3
Games like Victoria 3 include Europa Universalis IV, Victoria II, Imperator: Rome, Europa Universalis V, and Crusader Kings II. We matched them by the tags players give Victoria 3 on Steam (Strategy, Simulation, Grand Strategy, Economy, and Political Sim): closest matches first, and among equally close ones the better-known games.

Europa Universalis IV
Shared: Strategy · Grand Strategy · Simulation

Victoria II
Shared: Strategy · Grand Strategy · Simulation

Imperator: Rome
Shared: Strategy · Simulation · Grand Strategy

Europa Universalis V
Shared: Strategy · Grand Strategy · Simulation

Crusader Kings II
Shared: Strategy · Grand Strategy · Simulation

Manor Lords
Shared: Strategy · Simulation · Grand Strategy

Hearts of Iron IV
Shared: Strategy · Grand Strategy · Historical

Sid Meier's Civilization VII
Shared: Strategy · Grand Strategy · Simulation

Democracy 4
Shared: Strategy · Simulation · Political Sim

Crusader Kings III
Shared: Strategy · Grand Strategy · Simulation

Terra Invicta
Shared: Strategy · Simulation · Grand Strategy

Workers & Resources: Soviet Republic
Shared: Strategy · Simulation · Grand Strategy

Age of History II
Shared: Strategy · Grand Strategy · Historical

Rebel Inc: Escalation
Shared: Strategy · Simulation · Grand Strategy

Against the Storm
Shared: Strategy · Simulation · Grand Strategy

Cities: Skylines
Shared: Simulation · Strategy · Economy

Empires of the Undergrowth
Shared: Strategy · Simulation · Grand Strategy

Plutocracy
Shared: Strategy · Simulation · Grand Strategy

Sid Meier’s Civilization® VI
Shared: Strategy · Grand Strategy · Historical

Stellaris
Shared: Strategy · Grand Strategy · Simulation

Old World
Shared: Strategy · Simulation · Grand Strategy

Tropico 6
Shared: Strategy · Simulation · Economy

Dummynation
Shared: Grand Strategy · Simulation · Strategy

Norland
Shared: Strategy · Simulation · Grand Strategy