Privacy (UK: , US: ) is the ability of an individual or group to seclude themselves or information about themselves, and thereby express themselves selectively.

Etymology of the word privacy: the word privacy is derived from the Latin word "privatus" which means set apart from what is public, personal and belonging to oneself, and not to the state.

The domain of privacy partially overlaps with security, which can include the concepts of appropriate use and protection of information. Privacy may also take the form of bodily integrity. The right not to be subjected to unsanctioned invasions of privacy by the government, corporations, or individuals is part of many countries' privacy laws, and in some cases, constitutions.

The concept of universal individual privacy is a modern concept primarily associated with Western culture, particularly British and North American, and remained virtually unknown in some cultures until recent times. Now, most cultures recognize the ability of individuals to withhold certain parts of personal information from wider society. With the rise of technology, the debate regarding privacy has shifted from a bodily sense to a digital sense. As the world has become digital, there have been conflicts regarding the legal right to privacy and where it is applicable. In most countries, the right to a reasonable expectation to digital privacy has been extended from the original right to privacy, and many countries, notably the US, under its agency, the Federal Trade Commission, and those within the European Union (EU), have passed acts that further protect digital privacy from public and private entities and grant additional rights to users of technology.

With the rise of the Internet, there has been an increase in the prevalence of social bots, causing political polarization and harassment. Online harassment has also spiked, particularly with teenagers, which has consequently resulted in multiple privacy breaches. Selfie culture, the prominence of networks like Facebook and Instagram, location technology, and the use of advertisements and their tracking methods also pose threats to digital privacy.

Through the rise of technology and immensity of the debate regarding privacy, there have been various conceptions of privacy, which include the right to be let alone as defined in "The Right to Privacy", the first U.S. publication discussing privacy as a legal right, to the theory of the privacy paradox, which describes the notion that users' online may say they are concerned about their privacy, but in reality, are not. Along with various understandings of privacy, there are actions that reduce privacy, the most recent classification includes processing of information, sharing information, and invading personal space to get private information, as defined by Daniel J. Solove. Conversely, in order to protect a user's privacy, multiple steps can be taken, specifically through practicing encryption, anonymity, and taking further measures to bolster the security of their data.