Tristan Tzara (Sami Rosenstock a.k.a. Samuel Rosenstock) (April 16, 1896 – December 25, 1963) was a Romanian poet and essayist. He was one of the founders of the Dada movement, known best for his manifestos. He was a collaborater with Marcel Janco. It is speculated that the word "Dada" comes from the Romanian "Yes, yes" and is thus originated from Tzara and Janco's contributions. It is more commonly believed Tzara picked a random word out of a French dictionary and got "Dada", a child's word for a hobby horse.

Tzara was born in Moineşti, Bacău, Romania to a family of Romanian-speaking Jewish ancestry. Tzara wrote the first Dada texts, La Première Aventure céleste de Monsieur Antipyrine (The First Heavenly Adventure of Mr. Antipyrine) (1916), Vingt-cinq poèmes (Twenty-Five Poems) (1918) [1], and the movement's manifestos, Sept manifestes Dada (Seven Dada Manifestos) (1924).

In Paris he engaged in tumultuous activities with Dadaists André Breton, Philippe Soupault, and Louis Aragon to shock the public and to disintegrate the structures of language.

In late 1929, weary of nihilism and destruction, he joined his friends in the activities of Surrealism. He devoted much of his time to the reconciliation of Surrealism and Marxism and joined the French Communist Party in 1937. He was active in the French Resistance movement during World War II. He left the Communist Party in 1956, in protest against the Soviet quelling of the Hungarian Revolution.

His political commitments brought him closer to his fellow human beings, and he gradually matured into a lyrical poet. His poems revealed the anguish of his soul, caught between revolt and wonderment at the daily tragedy of the human condition. His mature works started with L'Homme approximatif (The Approximate Man) (1931), and continued with Parler seul (Speaking Alone) (1950), and La Face intérieure (The Inner Face) (1953). In these, the anarchically scrambled words of Dada were replaced with a difficult but humanized language. He died in Paris and was interred there in the Cimetière du Montparnasse.