Authenticity in art is manifest in the different ways that a work of art, or an artistic performance, can be considered authentic. The initial distinction is between nominal authenticity and expressive authenticity. In the first sense, nominal authenticity is the correct identification of the author of a work of art; of how closely an actor or an actress interprets a role in a stageplay as written by the playwright; of how well a musician's performance of an artistic composition corresponds to the composer's intention; and how closely an objet d’art conforms to the artistic traditions of its genre. In the second sense, expressive authenticity is how much the work of art possesses inherent authority of and about its subject, and how much of the artist's intent is in the work of art.

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.