  We consider a generic mechanism via which thermal relic WIMP dark matter may
be decoupled from the Standard Model, namely through a combination of WIMP
annihilation to metastable mediators with subsequent delayed decay to Standard
Model states. We illustrate this with explicit examples of WIMPs connected to
the Standard Model by metastable bosons or fermions. In all models, provided
the WIMP mass is greater than that of the mediator, it can be secluded from the
Standard Model with an extremely small elastic scattering cross-section on
nuclei and rate for direct collider production. In contrast, indirect
signatures from WIMP annihilation are consistent with a weak scale
cross-section and provide potentially observable \gamma-ray signals. We also
point out that \gamma-ray constraints and flavor physics impose severe
restrictions on MeV-scale variants of secluded models, and identify limited
classes that pass all the observational constraints.
