The proposition that existence precedes essence (French: l'existence précède l'essence) is a central claim of existentialism, which reverses the traditional philosophical view that the essence (the nature) of a thing is more fundamental and immutable than its existence (the mere fact of its being). To existentialists, human beings—through their consciousness—create their own values and determine a meaning for their life because the human being does not possess any inherent identity or value. That identity or value must be created by the individual. By posing the acts that constitute them, they make their existence more significant.

The idea originates from a speech by F. W. J. Schelling delivered in December 1841. Søren Kierkegaard was present at this occasion and the idea can be found in Kierkegaard's works in the 19th century, but was explicitly formulated by philosopher Jean-Paul Sartre in the 20th century. The three-word formula originated in his 1945 lecture "Existentialism Is a Humanism", though antecedent notions can be found in Heidegger's Being and Time.