The word capsule, or encapsulation, may refer to:
- Capsule (anatomy), a cover or envelope partly or wholly surrounding a structure.
- Capsule (microbiology), a layer that lies outside the cell wall of bacteria.
- Capsule (pharmacy), a small gelatinous case enclosing a dose of medication.
- Another name for the sporangium of mosses and hornworts.
- Capsular contracture, the scar tissue naturally forming around breast implants.