Games like Ominous
Games like Ominous include Escape the Backrooms, Backrooms: Escape Together, Phasmophobia, Lethal Company, and Pacify. We matched them by the tags players give Ominous on Steam (Horror, Online Co-Op, Multiplayer, Psychological Horror, and First-Person): closest matches first, and among equally close ones the better-known games.

Escape the Backrooms
Shared: Horror · Online Co-Op · Multiplayer

Backrooms: Escape Together
Shared: Horror · Multiplayer · Online Co-Op

Phasmophobia
Shared: Horror · Online Co-Op · Multiplayer

Lethal Company
Shared: Horror · Online Co-Op · First-Person

Pacify
Shared: Horror · Online Co-Op · Multiplayer

PEAK
Shared: Online Co-Op · Multiplayer · First-Person

Inside the Backrooms
Shared: Horror · Multiplayer · Psychological Horror

Outlast
Shared: Horror · First-Person · Psychological Horror

Content Warning
Shared: Horror · Online Co-Op · Multiplayer

R.E.P.O.
Shared: Horror · Online Co-Op · Multiplayer

DEVOUR
Shared: Horror · Online Co-Op · Multiplayer

The Outlast Trials
Shared: Horror · Multiplayer · Psychological Horror

Demonologist
Shared: Horror · Online Co-Op · Multiplayer

Dead by Daylight
Shared: Horror · Multiplayer · Online Co-Op

Zort
Shared: Horror · Online Co-Op · Psychological Horror

Nuclear Nightmare
Shared: Online Co-Op · Horror · First-Person

Fears to Fathom® - Scratch Creek
Shared: Horror · Multiplayer · Psychological Horror

Subnautica 2
Shared: Horror · Multiplayer · Exploration

RV There Yet?
Shared: Multiplayer · Online Co-Op · First-Person

Visage
Shared: Horror · Psychological Horror · Multiplayer

Little Nightmares II
Shared: Horror · Psychological Horror · Adventure

PANICORE
Shared: Horror · Online Co-Op · Psychological Horror

Species: Unknown
Shared: Horror · Online Co-Op · First-Person

Buckshot Roulette
Shared: Multiplayer · Horror · Dark