The true self (also known as real self, authentic self, original self and vulnerable self) and the false self (also known as fake self, idealized self, superficial self and pseudo self) are a psychological dualism conceptualized by English psychoanalyst Donald Winnicott. Winnicott used "true self" to denote a sense of self based on spontaneous authentic experience and a feeling of being alive, having a real self with little to no contradiction. "False self", by contrast, denotes a sense of self created as a defensive facade, which in extreme cases can leave an individual lacking spontaneity and feeling dead and empty behind an inconsistent and incompetent appearance of being real, such as in narcissism.

In his work, Winnicott saw the "true self" as stemming from self-perception in early infancy, such as awareness of tangible aspects of being alive, like blood pumping through veins and lungs inflating and deflating with breathing—what Winnicott called simply being. Out of this, an infant begins to guarantee that these elements are constant, and regards its life as an essential reality. After birth, the baby's spontaneous, nonverbal gestures derive from that instinctual sense and, if responded to kindly and with affirmation by the parents, become the basis for the continuing development of the true self.

However, when what Winnicott was careful to describe as good enough parenting—i.e., not necessarily perfect—was not in place, the infant's spontaneity was in danger of being encroached on by the need for compliance with the parents' wishes/expectations. The result could be the creation of what Winnicott called the "false self", where "other people's expectations can become of overriding importance, overlaying or contradicting the original sense of self, the one connected to the very roots of one's being". The danger he saw was that "through this false self, the infant builds up a false set of relationships, and by means of introjections even attains a show of being real", while, in fact, merely concealing a barren emptiness behind an independent-seeming façade.

The danger was particularly acute when the baby had to provide attunement for the mother/parents, rather than vice versa, building up a sort of dissociated recognition of the object on an impersonal, not personal and spontaneous basis. But while such a pathological false self stifled the spontaneous gestures of the true self in favour of a lifeless imitation, Winnicott nevertheless considered it of vital importance in preventing something worse: the annihilating experience of the exploitation of the hidden true self itself.

Helene Deutsch, a colleague of Freud, had previously described "as if" personalities, pseudo-relationships substituting for real ones. Winnicott's analyst, Joan Riviere, had also explored the concept of the narcissist's masquerade, which is essentially a superficial assent concealing a subtle hidden struggle for control. Freud's own late theory of the ego as the product of identifications came close to viewing it only as a false self; while Winnicott's true/false distinction has also been compared to Michael Balint's "basic fault" and to Ronald Fairbairn's notion of the "compromised ego".

Erich Fromm, in his 1941 book The Fear of Freedom distinguished between original self and pseudo self—the inauthenticality of the latter being a way to escape the loneliness of freedom; while much earlier existentialists such as Søren Kierkegaard had claimed that "to will to be that self which one truly is, is indeed the opposite of despair"—the despair of choosing "to be another than himself".

Karen Horney, in her 1950 book, Neurosis and Human Growth, based her idea of "true self" and "false self" through the view of self-improvement, interpreting it as real self and ideal self, with the real self being what one currently is and the ideal self being what one could become. (See also Karen Horney § Theory of the self).

The second half of the twentieth century saw Winnicott's ideas extended and applied in a variety of contexts, both in psychoanalysis and beyond.