Cf or CF may stand for:
- Californium, symbol for the chemical element
- Central African Republic, ISO country code
- Compact Flash, a solid state memory technology
- Cystic Fibrosis, an autosomal recessive hereditary disease
- Call forwarding, a telecommunication service feature
- center field, a fielding position in baseball
- Cluster fuck alias Charlie Foxtrot
- Cf. is also an abbreviation for the Latin word confer, meaning "compare."