Personally Identifiable Information (PII), as used in information security, refers to information that can be used to uniquely identify, contact, or locate a single person or can be used with other sources to uniquely identify a single individual. Personally identifiable information (PII) includes any data about an individual that could, potentially identify that person, such as a name, fingerprints or other biometric data, email address, street address, telephone number or social security number.