Confidentiality is the state of keeping or being kept secret or private.

Confidentiality is an important principle in healthcare because it defines the boundary on the amount of personal information and data that can be disclosed without consent. The relationship between healthcare professionals and their patients centres on trust, and trust is dependent on the patient being confident that personal information they disclose is treated confidentially.

However confidentiality can be countered, when there is a public interest in others being protected from harm.