Games like Stardew Valley
Games like Stardew Valley include Sun Haven, Fields of Mistria, My Time at Portia, Coral Island, and Clanfolk. We matched them by the tags players give Stardew Valley on Steam (Farming Sim, Pixel Graphics, Multiplayer, Life Sim, and RPG): closest matches first, and among equally close ones the better-known games.

Sun Haven
Shared: Farming Sim · Pixel Graphics · Multiplayer

Fields of Mistria
Shared: Farming Sim · Pixel Graphics · Life Sim

My Time at Portia
Shared: Farming Sim · Life Sim · RPG

Coral Island
Shared: Farming Sim · Life Sim · Relaxing

Clanfolk
Shared: Farming Sim · Pixel Graphics · Life Sim

My Time at Sandrock
Shared: Farming Sim · Life Sim · Multiplayer

Littlewood
Shared: Pixel Graphics · Life Sim · RPG

Terraria
Shared: Multiplayer · Pixel Graphics · Sandbox

Dinkum
Shared: Farming Sim · Relaxing · Life Sim

Palia
Shared: Multiplayer · Farming Sim · Life Sim

Infinity Nikki
Shared: Relaxing · Multiplayer · RPG

Farm Together
Shared: Multiplayer · Farming Sim · Agriculture

Graveyard Keeper
Shared: Pixel Graphics · RPG · Simulation

I Am Future: Cozy Apocalypse Survival
Shared: Farming Sim · RPG · Simulation

Roots of Pacha
Shared: Farming Sim · Pixel Graphics · Life Sim

Starsand Island
Shared: Farming Sim · Life Sim · RPG

DAVE THE DIVER
Shared: Pixel Graphics · Relaxing · Farming Sim

Forager
Shared: Pixel Graphics · Farming Sim · Crafting

Travellers Rest
Shared: Pixel Graphics · Farming Sim · Life Sim

Potion Craft: Alchemist Simulator
Shared: Relaxing · Simulation · Crafting

Little Witch in the Woods
Shared: Pixel Graphics · Life Sim · Simulation

Farming Simulator 19
Shared: Farming Sim · Multiplayer · Simulation

Farmer's Dynasty - Final Harvest Edition
Shared: Farming Sim · Life Sim · Simulation

Core Keeper
Shared: Pixel Graphics · Multiplayer · Sandbox