Authenticity is a concept of personality in the fields of psychology, existential psychotherapy, existentialist philosophy, and aesthetics. In existentialism, authenticity is the degree to which a person's actions are congruent with their values and desires, despite external pressures to social conformity. The conscious self comes to terms with the condition of Geworfenheit, of having been thrown into an absurd world not of their own making, thereby encountering external forces and influences different from and other than the Self. A person’s lack of authenticity is considered bad faith in dealing with other people and with one's self; thus, authenticity is in the instruction of the Oracle of Delphi: “Know thyself.” Concerning authenticity in art, the philosophers Jean Paul Sartre and Theodor Adorno held opposing views and opinions about jazz, a genre of American music; Sartre said that jazz is authentic and Adorno said that jazz is inauthentic. Many musical subcultures require artistic authenticity, lest the community consider an artist to be a poseur for lacking authenticity ; artistic authenticity is integral to many genres of music, including but not limited to genres of rock, club music, and hip-hop.

Existentialism is a form of philosophical inquiry that explores the issue of human existence. Existentialist philosophers explore questions related to the meaning, purpose, and value of human existence. Common concepts in existentialist thought include existential crisis, dread, and anxiety in the face of an absurd world and free will, as well as authenticity, courage, and virtue.