This is a list of notable massively multiplayer online games (MMOG), sorted by category.
Massively multiplayer online first-person shooter games (MMOFPS) edit
Massively multiplayer online role-playing games (MMORPG) edit
Massively multiplayer online real-time strategy games (MMORTS) edit
Massively multiplayer online turn-based strategy games edit
Action edit
Browser games edit
- Agar.io
- Bin Weevils
- Blood Wars
- Castle of Heroes
- Club Penguin
- Command & Conquer: Tiberium Alliances
- Dark Orbit
- Empire & State
- Hattrick
- Ikariam
- Illyriad
- Imperia Online
- Little Space Heroes
- Lord of Ultima
- Miniconomy
- National Geographic Animal Jam
- NEO Shifters
- Ogame
- Omerta
- Pardus
- Pirate Galaxy
- Planetarion
- Poptropica
- Realm of the Mad God
- Runes of Magic
- Samurai Taisen
- Sentou Gakuen
- Slither.io
- Smallworlds
- Surviv.io
- Tenvi
- Terra Militaris
- TirNua
- Transformice
- Travian
- Tribal Wars
- Twin Skies
- Urban Dead
- World of the Living Dead: Resurrection
Browser games with 3D rendering edit
Building games edit
Exploration edit
Puzzle edit
Social games edit
- Active Worlds
- Animal Jam Classic
- Bin Weevils
- EGO
- Flyff
- Free Realms
- Furcadia
- Habbo
- JumpStart
- Nicktropolis
- OurWorld
- Pirate101 (sister game to Wizard101)
- Red Light Center
- Second Life
- The Sims Online
- SmallWorlds
- Star Wars: The Old Republic
- Tanki Online
- There
- TirNua
- Toontown Online
- Transformice
- Virtual Magic Kingdom
- Virtual World of Kaneva
- vSide
- Wizard101 (sister game to Pirate101)
- Woozworld