Many different types of ghosts exist, splitting into three categories, but all connected to the world by a respective Source each.
- Main article: Type One
The most common and weakest forms of ghosts. Commonly encountered sub-types are Shades, Lurkers, Stalkers, Cold Maidens, Floating Brides, Glimmers, Pale Stenches, Stone Knockers and Tom O'Shadows.
- Main article: Type Two
The most dangerous common ghosts. They are stronger than Type Ones and possess some kind of limited intelligence. They are aware of the living and they might attempt to harm them. Commonly encountered sub-types in order are Spectres, Phantasms, Wraiths, Dark Spectres, Fetches, Limbless, Poltergeists, Raw-Bones and Shining Boys.
- Main article: Type Three
The most uncommon type of ghost that is said to be able to talk with those with the proper Talent, but also to be perverse and dangerous. Marissa Fittes of the Fittes Agency was said to have long conversations with Type Three ghosts, while some question whether they even exist. The only known Type Three ghost is the skull, which has only ever spoken to Lucy Carlyle, a fact only the Lockwood & Co. agency is aware of.