An informant is a person who provides privileged information to an agency.

Informant may also refer to:

• Informant (linguistics), a native speaker who provides information about their language for linguistics study
• Informant (psychiatry), a third party who can report on a psychiatric case for a doctor
• Informant (statistics), the gradient of the log-likelihood function, also known as the score (function).

• Informer (disambiguation)
• The Informant (disambiguation)